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SERVICE MANUAL
Sec. 1: Main Section
I Specifications I Preparation for Servicing I Adjustment Procedures I Schematic Diagrams I CBA's

Sec. 2: Deck Mechanism Section
I Standard Maintenance I Alignment for Mechanism I Disassembly/Assembly of Mechanism I Alignment Procedures of Mechanism

Sec. 3: Exploded views and Parts List Section
I Exploded views I Parts List

VIDEO CASSETTE RECORDER
25C-854

PAL

SECAM

MAIN SECTION
VIDEO CASSETTE RECORDER 25C-854

Sec. 1: Main Section
I Specifications I Preparation for Servicing I Adjustment Procedures I Schematic Diagrams I CBA's

TABLE OF CONTENTS
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1-1 Important Safety Precautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2-1 Standard Notes for Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3-1 Preparation for Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4-1 Cabinet Disassembly Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5-1 Electrical Adjustment Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6-1 Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7-1 Function Indicator Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7-11 Schematic Diagrams / CBA's and Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8-1 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9-1 Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10-1 IC Pin Function Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-11-1 Lead Identifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12-1

SPECIFICATIONS
Description 1. Video 1-1. Video Output (PB) 1-2. Video Output (R/P) 1-3. Video S/N Y (R/P) 1-4. Video Color S/N AM (R/P) 1-5. Video Color S/N PM (R/P) 1-6. Resolution (PB) 2. Servo 2-1. Jitter Low 2-2. Wow & Flutter 3. Normal Audio 3-1. Output (PB) 3-2. Output (R/P) 3-3. S/N (R/P) 3-4. Distortion (R/P) 3-5. Freq. resp (R/P) at 200Hz (-20dB ref. 1kHz) at 6kHz 4. Tuner 4-1. Video output 4-2. Video S/N 4-3. Audio output 4-4. Audio S/N 5. Hi-Fi Audio 5-1. Output 5-2. Dynamic Range 5-3. Freq. resp (6dB B.W) dBV dB Hz -12 70 -8 85 20 ~ 20K -4 SP Mode SP Mode SP Mode Vp-p dB dB dB 0.8 39 -10 40 1.0 42 -6 46 -2 1.2 E-E Mode E-E Mode E-E Mode E-E Mode dBV dBV dB % dB dB -7 -10 -9 -9 36 -6 -6 41 1.0 -4 -4 4.0 -3 -1.5 SP Mode SP Mode SP Mode SP Mode SP Mode SP Mode µsec % 0.07 0.3 0.12 0.5 SP Mode SP Mode Vp-p Vp-p dB dB dB Line 0.8 0.8 40 37 30 230 1.0 1.0 45 41 36 245 1.2 1.2 SP Mode, W/O Burst SP Mode SP Mode SP Mode FL6A Unit Minimum Nominal Maximum Remark

Note: Nominal specs represent the design specs. All units should be able to approximate these ­ some will exceed and some may drop slightly below these specs. Limit specs represent the absolute worst condition that still might be considered acceptable; In no case should a unit fail to meet limit specs.

1-1-1

HC4C0SP

IMPORTANT SAFETY PRECAUTIONS
Product Safety Notice
Some electrical and mechanical parts have special safety-related characteristics which are often not evident from visual inspection, nor can the protection they give necessarily be obtained by replacing them with components rated for higher voltage, wattage, etc. Parts that have special safety characteristics are identified by a ! on schematics and in parts lists. Use of a substitute replacement that does not have the same safety characteristics as the recommended replacement part might create shock, fire, and/or other hazards. The Product's Safety is under review continuously and new instructions are issued whenever appropriate. Prior to shipment from the factory, our products are carefully inspected to confirm with the recognized product safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following precautions when a set is being serviced. I. Also check areas surrounding repaired locations. J. Be careful that foreign objects (screws, solder droplets, etc.) do not remain inside the set. K. Crimp type wire connector The power transformer uses crimp type connectors which connect the power cord and the primary side of the transformer. When replacing the transformer, follow these steps carefully and precisely to prevent shock hazards. Replacement procedure 1)Remove the old connector by cutting the wires at a point close to the connector. Important: Do not re-use a connector. (Discard it.) 2)Strip about 15 mm of the insulation from the ends of the wires. If the wires are stranded, twist the strands to avoid frayed conductors. 3)Align the lengths of the wires to be connected. Insert the wires fully into the connector. 4)Use a crimping tool to crimp the metal sleeve at its center. Be sure to crimp fully to the complete closure of the tool. L. When connecting or disconnecting the internal connectors, first, disconnect the AC plug from the AC outlet.

Precautions during Servicing
A. Parts identified by the ! symbol are critical for safety. Replace only with part number specified. B. In addition to safety, other parts and assemblies are specified for conformance with regulations applying to spurious radiation. These must also be replaced only with specified replacements. Examples: RF converters, RF cables, noise blocking capacitors, and noise blocking filters, etc. C. Use specified internal wiring. Note especially: 1)Wires covered with PVC tubing 2)Double insulated wires 3)High voltage leads D. Use specified insulating materials for hazardous live parts. Note especially: 1)Insulation tape 2)PVC tubing 3)Spacers 4)Insulators for transistors E. When replacing AC primary side components (transformers, power cord, etc.), wrap ends of wires securely about the terminals before soldering. F. Observe that the wires do not contact heat producing parts (heatsinks, oxide metal film resistors, fusible resistors, etc.). G. Check that replaced wires do not contact sharp edges or pointed parts. H. When a power cord has been replaced, check that 5 - 6 kg of force in any direction will not loosen it. 1-2-1

H8740SFP

Safety Check after Servicing
Examine the area surrounding the repaired location for damage or deterioration. Observe that screws, parts, and wires have been returned to their original positions. Afterwards, do the following tests and confirm the specified values to verify compliance with safety standards.
Chassis or Secondary Conductor Primary Circuit Terminals d' d

1. Clearance Distance
When replacing primary circuit components, confirm specified clearance distance (d) and (d') between soldered terminals, and between terminals and surrounding metallic parts. (See Fig. 1) Table 1 : Ratings for selected area AC Line Voltage 230 V Clearance Distance (d) (d')

Fig. 1

3mm(d) 6 mm(d')

Exposed Accessible Part

Note: This table is unofficial and for reference only. Be sure to confirm the precise values.

2. Leakage Current Test
Confirm the specified (or lower) leakage current between B (earth ground, power cord plug prongs) and externally exposed accessible parts (RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks, etc.) is lower than or equal to the specified value in the table below. Measuring Method (Power ON) : Insert load Z between B (earth ground, power cord plug prongs) and exposed accessible parts. Use an AC voltmeter to measure across the terminals of load Z. See Fig. 2 and the following table.
Z AC Voltmeter (High Impedance)

B

One side of Power Cord Plug Prongs

Fig. 2

Table 2: Leakage current ratings for selected areas AC Line Voltage Load Z 2k RES. Connected in parallel 50k RES. Connected in parallel Leakage Current (i) i0.7mA AC Peak i2mA DC i0.7mA AC Peak i2mA DC One side of power cord plug prongs (B) to: RF or Antenna terminals A/V Input, Output

230 V

Note: This table is unofficial and for reference only. Be sure to confirm the precise values.

1-2-2

H8740SFP

STANDARD NOTES FOR SERVICING
Circuit Board Indications
a. The output pin of the 3 pin Regulator ICs is indicated as shown.
Top View Out In Input Bottom View

How to Remove / Install Flat Pack-IC
1. Removal
With Hot-Air Flat Pack-IC Desoldering Machine:. (1) Prepare the hot-air flat pack-IC desoldering machine, then apply hot air to the Flat Pack-IC (about 5 to 6 seconds). (Fig. S-1-1)

b. For other ICs, pin 1 and every fifth pin are indicated as shown.

5 Pin 1
Fig. S-1-1

10
(2) Remove the flat pack-IC with tweezers while applying the hot air. (3) Bottom of the flat pack-IC is fixed with glue to the CBA; when removing entire flat pack-IC, first apply soldering iron to center of the flat pack-IC and heat up. Then remove (glue will be melted). (Fig. S-1-6) (4) Release the flat pack-IC from the CBA using tweezers. (Fig. S-1-6)

c. The 1st pin of every male connector is indicated as shown.

Pin 1

Caution:

Instructions for Connectors
1. When you connect or disconnect the FFC (Flexible Foil Connector) cable, be sure to first disconnect the AC cord. 2. FFC (Flexible Foil Connector) cable should be inserted parallel into the connector, not at an angle.

1. Do not supply hot air to the chip parts around the flat pack-IC for over 6 seconds because damage to the chip parts may occur. Put masking tape around the flat pack-IC to protect other parts from damage. (Fig. S-1-2) 2. The flat pack-IC on the CBA is affixed with glue, so be careful not to break or damage the foil of each pin or the solder lands under the IC when removing it.
Hot-air Flat Pack-IC Desoldering Machine CBA

FFC Cable

Connector CBA

* Be careful to avoid a short circuit.
Masking Tape Tweezers Flat Pack-IC

Fig. S-1-2

1-3-1

NOTE_1

With Soldering Iron: (1) Using desoldering braid, remove the solder from all pins of the flat pack-IC. When you use solder flux which is applied to all pins of the flat pack-IC, you can remove it easily. (Fig. S-1-3)
Flat Pack-IC Desoldering Braid

(4) Bottom of the flat pack-IC is fixed with glue to the CBA; when removing entire flat pack-IC, first apply soldering iron to center of the flat pack-IC and heat up. Then remove (glue will be melted). (Fig. S-1-6) (5) Release the flat pack-IC from the CBA using tweezers. (Fig. S-1-6) Note: When using a soldering iron, care must be taken to ensure that the flat pack-IC is not being held by glue. When the flat pack-IC is removed from the CBA, handle it gently because it may be damaged if force is applied.
Hot Air Blower

Soldering Iron

Fig. S-1-3 (2) Lift each lead of the flat pack-IC upward one by one, using a sharp pin or wire to which solder will not adhere (iron wire). When heating the pins, use a fine tip soldering iron or a hot air desoldering machine. (Fig. S-1-4)
or

Iron Wire

Soldering Iron To Solid Mounting Point

Fig. S-1-5

Sharp Pin Fine Tip Soldering Iron
Fig. S-1-4 (3) Bottom of the flat pack-IC is fixed with glue to the CBA; when removing entire flat pack-IC, first apply soldering iron to center of the flat pack-IC and heat up. Then remove (glue will be melted). (Fig. S-1-6) (4) Release the flat pack-IC from the CBA using tweezers. (Fig. S-1-6) With Iron Wire: (1) Using desoldering braid, remove the solder from all pins of the flat pack-IC. When you use solder flux which is applied to all pins of the flat pack-IC, you can remove it easily. (Fig. S-1-3) (2) Affix the wire to a workbench or solid mounting point, as shown in Fig. S-1-5. (3) While heating the pins using a fine tip soldering iron or hot air blower, pull up the wire as the solder melts so as to lift the IC leads from the CBA contact pads as shown in Fig. S-1-5
Flat Pack-IC Tweezers

CBA

Fine Tip Soldering Iron

Fig. S-1-6

1-3-2

NOTE_1

2. Installation
(1) Using desoldering braid, remove the solder from the foil of each pin of the flat pack-IC on the CBA so you can install a replacement flat pack-IC more easily. (2) The " I " mark on the flat pack-IC indicates pin 1. (See Fig. S-1-7.) Be sure this mark matches the 1 on the PCB when positioning for installation. Then presolder the four corners of the flat pack-IC. (See Fig. S-1-8.) (3) Solder all pins of the flat pack-IC. Be sure that none of the pins have solder bridges.
Example :

Instructions for Handling Semi-conductors
Electrostatic breakdown of the semi-conductors may occur due to a potential difference caused by electrostatic charge during unpacking or repair work.

1. Ground for Human Body
Be sure to wear a grounding band (1M) that is properly grounded to remove any static electricity that may be charged on the body.

2. Ground for Workbench
Be sure to place a conductive sheet or copper plate with proper grounding (1M) on the workbench or other surface, where the semi-conductors are to be placed. Because the static electricity charge on clothing will not escape through the body grounding band, be careful to avoid contacting semi-conductors with your clothing. < Incorrect >

Pin 1 of the Flat Pack-IC is indicated by a " " mark.

Fig. S-1-7

Presolder

CBA

Flat Pack-IC CBA

Fig. S-1-8

< Correct >
Grounding Band

1M

CBA

1M Conductive Sheet or Copper Plate

1-3-3

NOTE_1

PREPARATION FOR SERVICING
How to Enter the Service Mode
About Optical Sensors Caution: An optical sensor system is used for the Tape Start and End Sensors on this equipment. Carefully read and follow the instructions below. Otherwise the unit may operate erratically. What to do for preparation Insert a tape into the Deck Mechanism Assembly and press the PLAY button. The tape will be loaded into the Deck Mechanism Assembly. Make sure the power is on, TP507 (SENSOR INHIBITION) to GND. This will stop the function of Tape Start Sensor, Tape End Sensor and Reel Sensors. (If these TPs are connected before plugging in the unit, the function of the sensors will stay valid.) See Fig. 1. Note: Because the Tape End Sensors are inactive, do not run a tape all the way to the start or the end of the tape to avoid tape damage.
(REC-SAFETY SW)

About REC-Safety Switch Caution: The REC-Safety Switch is directly mounted on the Main CBA. When the Deck Mechanism Assembly is removed from the Main CBA for servicing, this switch does not work automatically. What to do for preparation In order to record, press the Rec button while pushing REC-SAFETY SW on the Main CBA. See Fig. 1.

Q503

Q504 TP507 S-INH

SW506

Fig. 1

1-4-1

HC2C0PFS

CABINET DISASSEMBLY INSTRUCTIONS
1. Disassembly Flowchart
This flowchart indicates the disassembly steps to gain access to item(s) to be serviced. When reassembling, follow the steps in reverse order. Bend, route, and dress the cables as they were originally.
[1] Top Case [2] Front Assembly [3] VCR Chassis Unit [4] Jack CBA [5] Function CBA [6] Deck Assembly [7] Main CBA

(1): Identification (location) No. of parts in the figures (2): Name of the part (3): Figure Number for reference (4): Identification of parts to be removed, unhooked, unlocked, released, unplugged, unclamped, or desoldered. P=Spring, L=Locking Tab, S=Screw, CN=Connector *=Unhook, Unlock, Release, Unplug, or Desolder e.g. 2(S-2) = two Screws (S-2), 2(L-2) = two Locking Tabs (L-2) (5): Refer to "Reference Notes."

Reference Notes
CAUTION: Locking Tabs (L-1) and (L-2) are fragile. Be careful not to break them. 1. Release Locking Tab (L-3) and remove Screw (S-2), five Screws (S-3), three Screws (S-4) and Screw (S-5). Then, slowly lift the VCR Chassis Unit (Deck Assembly, Function CBA, Jack CBA and Main CBA) up. 2. When reassembling, solder wire jumpers as shown in Fig. 5. 3. Before installing the Deck Assembly, be sure to place the pin of LD-SW on Main CBA as shown in Fig. 6. Then, install the Deck Assembly while aligning the hole of Cam Gear with the pin of LD-SW, the shaft of Cam Gear with the hole of LD-SW as shown in Fig. 6.

2. Disassembly Method
REMOVAL ID/ LOC. No. [1] [2] PART REMOVE/*UNHOOK/ Fig. UNLOCK/RELEASE/ Note No. UNPLUG/DESOLDER 1 2 7(S-1) *3(L-1),*4(L-2) *(L-3), 5(S-3), 3(S-4), (S-5) Desolder, (S-6) Desolder 2(S-7), Desolder ----------

Top Case Front Assembly VCR Chassis Unit Jack CBA Function CBA Deck Assembly Main CBA

[3] [4] [5] [6] [7]

3 4 5 5,6 5

1 2,3 -


(1)


(2)


(3)


(4)


(5)

1-5-1

HC2C0DC

(S-1) (S-1)

(S-4) (S-3) [3]VCR Chassis Unit

(S-3) (S-5) (S-4) (S-3)

[1] Top Case

(S-1)

Fig. 1

(L-2)

(L-2)

(L-3)

Fig. 3

[4] Jack CBA (S-6)

[2] Front Assembly (L-1)

Desolder

Fig. 2

Fig. 4

1-5-2

HC2C0DC

FE Head

Cylinder Assembly Pin AC Head Assembly

SW507 LD-SW

[6] Deck Assembly

[7] Main CBA

[7] Main CBA (S-7)

[6] Deck Assembly Cam Gear Shaft Hole

[5] Function CBA Desolder from bottom From Cylinder Assembly From AC Head Assembly

Hole (S-7) LD-SW Pin [7] Main CBA

Fig. 6
From Capstan Motor Assembly Lead with white stripe

From FE Head

Lead with red stripe

Lead with white stripe

TOP VIEW Lead connections of Deck Assembly and Main CBA

Fig. 5

1-5-3

HC2C0DC

ELECTRICAL ADJUSTMENT INSTRUCTIONS
General Note: "CBA" is an abbreviation for "Circuit Board Assembly." NOTE: 1.Electrical adjustments are required after replacing circuit components and certain mechanical parts. It is important to do these adjustments only after all repairs and replacements have been completed. Also, do not attempt these adjustments unless the proper equipment is available. 2.To perform these alignment / confirmation procedures, make sure that the tracking control is set in the center position: Press either "L5? " or "K" button on the remote control unit first, then the "PLAY" button (Front Panel only).

Head Switching Position Adjustment
Purpose: To determine the Head Switching point during playback. Symptom of Misadjustment: May cause Head Switching noise or vertical jitter in the picture. Test point Adj.Point Mode PLAY (SP) Input -----

VR501 TP751(V-OUT) TP502(RF-SW) (Switching Point) (MAIN CBA) GND Tape FL6A Measurement Equipment Oscilloscope

Test Equipment Required
1.Oscilloscope: Dual-trace with 10:1 probe, V-Range: 0.001~50V/Div., F-Range: DC~AC-20MHz 2.Alignment Tape (FL6A)

Spec. 6.5H±1H (412.7µs±60µs)

Connections of Measurement Equipment

Oscilloscope Main CBA TP751 GND TP502 CH1 CH2 Trig. (+)

Figure 1

EXT. Syncronize Trigger Point V-Sync CH1 1.0H CH2 6.5H 0.5H

Switching Pulse
Reference Notes: Playback the Alignment tape and adjust VR501 so that the V-sync front edge of the CH1 video output waveform is at the 6.5H(412.7µs) delayed position from the rising edge of the CH2 head switching pulse waveform.

1-6-1

HC2C0EA

Servo/System Control Block Diagram

BLOCK DIAGRAMS

MAIN CBA
AL+5V

Q502
SW507 LD-SW D502 S-LED

TP501 CTL

IC501 (SERVO/SYSTEM CONTROL)

FUNCTION CBA
TP507 S-INH KEY SWITCH SW505 CH-UP IC561 (FIP DRIVER) FP562 CL506 3 1 CN652 3 1

97 CTL 84 FF/REW-L RS501 REMOTE SENSOR

KEY- 1 7 KEY- 2 8

KEY-1 KEY-2

KEY SWITCH

(DECK ASSEMBLY)
CL287 CONTROL HEAD

14 REMOCON-IN 9 95 94 10 4 80 79

LED CLOCK

5 6

CTL(+) CTL(-)

CL504 5 6 TP506 END-S Q503

AL+5V

AC HEAD ASSEMBLY

PS503 S-REEL TIMER+5V

Q501 RESET SW508 RESET

LD-SW CTL(+) CTL(-) ST-S END-S T-REEL S-REEL

DRV-DATA 68 DRV-STB 69 DRV-CLK 70

28 DRV-DATA G1 23 2 DRV-STB G2 22 1 DRV-CLK G3 21 G4 20

S1 7 S2 8 S7 S8 S9 S10
13 14 16 17

Q504 ST-S

T-REEL

34 RESET

TU701(TUNER UNIT)
3 12 5 11

SENSOR CBA

SDA SDA SCL SCL

IC503 (MEMORY)
Q505 END-S
5 SDA 6 SCL

SENSOR CBA
VR501 SW-POINT AL+5V AL+5V SW506 REC-SAFETY
78 C-F/R 2 PG-DELAY 31 REC-SAF-SW

A-MUTE-H 83

IICBUS-SDA IICBUS-SCL A-MUTE-H IICBUS-SDA IICBUS-SCL Hi-Fi-H-SW A-MODE IICBUS-SDA IICBUS-SCL D-REC-H RF-SW C-ROTA D-V SYNC V-ENV C-SYNC H-A-SW H-A-COMP SECAM-H TRICK-H DAVN-L

TO AUDIO BLOCK

CYLINDER ASSEMBLY
PG SENSOR

CAPSTAN MOTOR
CAPSTAN MOTOR

M

DRUM MOTOR

M

LOADING MOTOR

M

12 11 10 9 8 7 6 5 4 3 2 1

CL502 C-F/R AL+15V/+12V AL+12V P-ON+5V GND C-FG C-CONT GND D-FG LM-FWD/REV D-CONT D-PG TO POWER SUPPLY BLOCK

AL+15V/+12V AL+12V P-ON+5V
87 C-FG 76 C-CONT 89 81 77 90

Hi-Fi-H-SW 19 A-MODE 61 I2C-BUS SDA I2C-BUS SCL D-REC-H RF-SW C-ROTA D-V SYNC V-ENV C-SYNC H-A-SW H-A-COMP SECAM-H TRICK-H DAVN-L
72 71 65 18 15 13 6 58 16 17 32 33 20

TO Hi-Fi AUDIO BLOCK

D-FG LM-FWD/REV D-CONT D-PG

TO VIDEO BLOCK

C-POW-SW P-ON-H P-DOWN-L

66 C-POW-SW 67 P-ON-H 86 P-DOWN-L

1-7-1

1-7-2

HC4S7BLS

Video Block Diagram
REC-VIDEO SIGNAL PB-VIDEO SIGNAL IC640 (VPS)
DAVN-L IIC BUS-SDA IIC BUS-SCL OSD-V-IN 14 6 7 16

MODE: SP/REC

MAIN CBA
TO SERVO/SYSTEM CONTROL BLOCK
IC501 (OSD)

VPS CBA

DAVN-L IIC BUS-SDA IIC BUS-SCL

DAVN-L IIC BUS-SDA IIC BUS-SCL VPS-V

52

OSD CHARACTER MIX

50

COLOR 55 -IN

Q351 BUFFER

IC301 (Y/C SIGNAL PROCESS)

65

43

46

68 69

78

79

Y. DELAY

SERIAL DECORDER
CL253 V(R)-1 V-COM V(L)-1 V(L)-2 V-COM V(R)-2

(DECK ASSEMBLY)
CYLINDER ASSEMBLY
1 2 3 4 5 6

TU701 VIDEO 6 TU-VIDEO 24
48 50 52 54 56
TUNER IN1 IN2 FRT IN2 FRT PB/EE MUTE TUNER IN1 PB/EE MUTE

LUMINANCE SIGNAL PROCESS
BYPASS AGC

R

P

SP EP

SP HEAD AMP

96 95 93 94

VIDEO (R)-1 HEAD VIDEO (L)-1 HEAD VIDEO (L)-2 HEAD VIDEO (R)-2 HEAD

JK756 V-IN-F

CHARA. INS. 1/2

CCD 1H DELAY

Y

+
C

REC FM AGC

EP HEAD AMP

90 89 88 87

WF2 TP502 RF-SW

CHROMINANCE SIGNAL PROCESS
R PR P

D-REC-H 80 RF-SW/C-ROTA D-V-SYNC H-A-SW H-A-COMP V-ENV C-SYNC
70 62 71 83 84 67

JACK CBA

WF1 TP751 V-OUT

FBC

Y/C MIX
P

JK101 Q101 CL101 1 BUFFER V-OUT1 19 3 20 V-IN1 JK102 Q102 CL102 1 V-OUT2 19 BUFFER 3 20 V-IN2

CL151
V-OUT1 V-IN1 1 3 61 63

R

D-REC-H RF-SW C-ROTA D-V-SYNC H-A-SW H-A-COMP V-ENV C-SYNC TRICK-H SECAM-H

TO SERVO/SYSTEM CONTROL BLOCK

AGC

VXO PB-H OUT

CL152
V-OUT2 V-IN2 1 3 58 59 28 29 25 21

44 28 1 29 17 14 18 2 16

IC370 (PAL/SECAM DECTECOTR)

X301 4.43MHz

TP301 C-PB WF5

PAL/SECAM DETECTOR

1-7-3

1-7-4

HC4S7BLV

Audio Block Diagram
PB-AUDIO SIGNAL REC-AUDIO SIGNAL
Mode : SP/REC

MAIN CBA

TO Hi-Fi AUDIO BLOCK

N-A-PB N-A-REC

IC301 (AUDIO SIGNAL PROCESS)

13 TUNER

15 IN1

17 IN2 ALC DET

12 LINE AMP MUTE 11

PB-ON 5 6 EQ AMP SP/LP-ON +5V 7 8 9

INV R ATT P

ALC

(DECK ASSEMBLY)

ACE HEAD ASSEMBLY
AUDIO HEAD AUDIO ERASE HEAD CL287 A-PB/REC A-COM AE-H AE-H/FE-H 4 3 1 2 4 3 1 2 CL504 A-PB/REC A-COM AE-H AE-H/FE-H Q401 Q402 BIAS OSC 1 2 Q406 AUTO BIAS 3 100 REC AMP REC-ON

Q404 (PB=ON)

FE HEAD
FULL ERASE HEAD CL501 2 FE-H 1 FE-H-GND Q405 (PB=ON)

SWITCHING Q403 D-REC-OFF +5V

AUDIO HD-SW CONTROL 16

SERIAL DECODER

68 69

71

A-MUTE-H IIC BUS-SDA IIC BUS-SCL

TO SERVO/SYSTEM CONTROL BLOCK

1-7-5

1-7-6

HC4S7BLA

Hi-Fi Audio Block Diagram

PB-AUDIO SIGNAL

REC-AUDIO SIGNAL

Mode : SP/REC

JK101 A-IN1(R) A-IN1(L) A-OUT1(R) A-OUT1(L)
2 6 1 3

CL101 10 8 6 12 CL102 9 8 6 11

A-IN1(R) A-IN1(L) A-OUT1(R) A-OUT1(L)

CL151 10 8 6 12
JK751 A-OUT(R)

MAIN CBA

JK102 A-IN2(R) A-IN2(L) A-OUT2(R) A-OUT2(L)
2 6 1 3

CL152 9 A-IN2(R) A-IN2(L) 8 A-OUT2(R) 6 A-OUT2(L) 11

FRONT
A-OUT(L)

JACK CBA

TU701
21 TU-AUDIO 22 SIF 76 75

IC451 (MTS/ SAP/ Hi-Fi AUDIO PROCESS/ Hi-Fi HEAD AMP)

SW SW ALC D.C. ALC D.C. R-CH PNR P R LIM
69 73 71 51 65 47

SW NOISE

COMP

R-CH BPF

SERIAL DATA DECODER

38 39

IIC BUS-SDA IIC BUS-SCL

DEV

VCO

LPF

DO DET

ENV DET

Q451
23

A-MODE

JK758 A-IN(R)

R-CH INSEL

48

TO SERVO/ SYSTEM CONTROL BLOCK
OUTPUT SELECT ALC MUTE
80 2 78

FRONT
JK757 A-IN(L)

67 7 11 9 53

HOLD PULSE L-CH INSEL
13 14

40

Hi-Fi-H-SW

NOISE DET LIM DEV VCO

MIX

COMP

26

CN701 CN1 CN1 CN701 2 SIF 2 4 TU-AUDIO(R) 4 IF SINAL PROCESS 1 TU-AUDIO 1 5 TU-AUDIO(L) 5

AFV CBA

LPF
CL253 Hi-Fi-A(R) Hi-Fi-COM Hi-Fi-A(L)

CYLINDER ASSEMBLY
R
24 27 7 8 9

NOR SW

L-CH PNR

R P SW NOISE

COMP

L-CH BPF

LIM

31

30

Hi-Fi AUDIO (R) HEAD Hi-Fi AUDIO (L) HEAD

L

TO AUDIO BLOCK

N-A-REC N-A-PB

6 4

1-7-7

1-7-8

HC4S7BLH

Power Supply Block Diagram
NOTE : The voltage for parts in hot circuit is measured using hot GND as a common terminal. CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE T1.6AL/250V FUSE. CAUTION ! Fixed voltage (or Auto voltage selectable ) power supply circuit is used in this unit. If Main Fuse (F001) is blown, check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply. Otherwise it may cause some components in the power supply circuit to fail.

MAIN CBA
HOT CIRCUIT. BE CAREFUL.

F001 T1.6A L 250V AC001

L003 LINE FILTER

D001 - D004 BRIDGE RECTIFIER
2

T001 Q051
12

Q053

Q052
13

Q057
4 14

Q058 Q001
15

P-ON+44V P-ON-H AL+15V/+12V AL+9V AL+12V C-POW-SW AL+5V TIMER+5V P-ON+5V P-DOWN-L

Q054
16

Q002
11

7

17

6

18

Q056 IC001 ERROR VOLTAGE DET
4 1

Q003

HOT

3

2

REG Q004 (SHUNT REGULATOR)

COLD

1-7-9

1-7-10

HC4S7BLP

FUNCTION INDICATOR SYMBOLS
Note: The following symbols will appear on the indicator panel to indicate the current mode or operation of the VCR. On-screen modes will also be momentarily displayed on the tv screen when you press the operation buttons.

Display panel

" H "= LED Light on, " L "= LED Light off LED MODE CASSETTE "IN" CASSETTE "OUT" CLOCK POWER ON REC REC PAUSE T-REC,OTR " " " 88:88 " PWR." " REC " " REC " " " " " INDICATOR ACTIVE ON OFF ON ON ON Blinks at 0.8Hz interval ON (T-REC OFF,T-REC incomplete Blinks at 0.8Hz interval) Blinks at 0.8Hz interval Blinks at 0.8Hz interval Blinks at 0.8Hz interval Blinks at 0.8Hz interval Blinks at 0.8Hz interval Blinks at 0.8Hz interval

When reel and capstan mechanism is not functioning correctly When tape loading mechanism is not functioning correctly When cassette loading mechanism is not functioning correctly When the drum is not working properly P-ON Power safety detection S-INH condition

" " " " " " " " " "

1 2 3

" " " " " "

" 4 " 5 " "

All modes

1-7-11

HC460FIS

SCHEMATIC DIAGRAMS / CBA'S AND TEST POINTS
Standard Notes WARNING
Many electrical and mechanical parts in this chassis have special characteristics. These characteristics often pass unnoticed and the protection afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts that have these special safety characteristics are identified in this manual and its supplements; electrical components having such features are identified by the mark " ! " in the schematic diagram and the parts list. Before replacing any of these components, read the parts list in this manual carefully. The use of substitute replacement parts that do not have the same safety characteristics as specified in the parts list may create shock, fire, or other hazards.

Notes:
1. Do not use the part number shown on these drawings for ordering. The correct part number is shown in the parts list, and may be slightly different or amended since these drawings were prepared. 2. All resistance values are indicated in ohms (K=103, M=106). 3. Resistor wattages are 1/4W or 1/6W unless otherwise specified. 4. All capacitance values are indicated in µF (P=10-6 µF). 5. All voltages are DC voltages unless otherwise specified. 6. Electrical parts such as capacitors, connectors, diodes, IC's, transistors, resistors, switches, and fuses are identified by four digits. The first two digits are not shown for each component. In each block of the diagram, there is a note such as shown below to indicate these abbreviated two digits.

Capacitor Temperature Markings
Mark (B) (F) (SR) (Z) Capacity change rate Standard temperature 20°C 20°C 20°C 20°C Temperature range -25~+85°C -25~+85°C -25~+85°C -10~+70°C

±10%
+30 - 80%

±15%
+30 - 80%

Capacitors and transistors are represented by the following symbols.

CBA Symbols
(Top View) (Bottom View) + Electrolytic Capacitor

Schematic Diagram Symbols
Digital Transistor

(Bottom View)

Transistor or Digital Transistor
E C B (Top View)

(Top View)

NPN Transistor
ECB ECB

PNP Transistor

(Top View)

(Top View)

NPN Digital Transistor
ECB ECB

PNP Digital Transistor

1-8-1

SCPA1

LIST OF CAUTION, NOTES, AND SYMBOLS USED IN THE SCHEMATIC DIAGRAMS ON THE FOLLOWING PAGES: 1. CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE FUSE. 2. CAUTION: Fixed Voltage (or Auto voltage selectable) power supply circuit is used in this unit. If Main Fuse (F001) is blown, first check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply. Otherwise it may cause some components in the power supply circuit to fail. 3. Note: (1) Do not use the part number shown on the drawings for ordering. The correct part number is shown in the parts list, and may be slightly different or amended since the drawings were prepared. (2) To maintain original function and reliability of repaired units, use only original replacement parts which are listed with their part numbers in the parts list section of the service manual. 4. Wire Connectors (1) Prefix symbol "CN" means "connector" (can disconnect and reconnect). (2) Prefix symbol "CL" means "wire-solder holes of the PCB" (wire is soldered directly). 5. Mode: SP/REC 6. Voltage indications for PLAY and REC modes on the schematics are as shown below:

Unit: Volts

1 5.0

2

3 5.0 (2.5)

PLAY mode REC mode

The same voltage for both PLAY & REC modes

Indicates that the voltage is not consistent here.

7. How to read converged lines

1-D3 Distinction Area Line Number (1 to 3 digits) Examples: 1. "1-D3" means that line number "1" goes to area "D3". 2. "1-B1" means that line number "1" goes to area "B1".

3 AREA D3 2 1 A

1-B1

AREA B1 1-D3 B C D

8. Test Point Information

: Indicates a test point with a jumper wire across a hole in the PCB. : Used to indicate a test point with a component lead on foil side. : Used to indicate a test point with no test pin. : Used to indicate a test point with a test pin.

1-8-2

SCRK05

Main 1/6 Schematic Diagram

1-8-3

1-8-4

1-8-5

HC4S7SCM1

Main 2/6 Schematic Diagram

1-8-6

1-8-7

1-8-8

HC4S7SCM2

Main 3/6 Schematic Diagram

1-8-9

1-8-10

1-8-11

HC4S7SCM3

Main 4/6 Schematic Diagram

NOTE : THE VOLTAGE FOR PARTS IN HOT CIRCUIT IS MEASURED USING HOT GND AS A COMMON TERMINAL.

CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE FUSE.

CAUTION ! Fixed voltage (or Auto voltage selectable ) power supply circuit is used in this unit. If Main Fuse (F001) is blown, check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply. Otherwise it may cause some components in the power supply circuit to fail.

1-8-12

1-8-13

1-8-14

HC4S7SCM4

Main 5/6 Schematic Diagram

1-8-15

1-8-16

HC4S7SCM5

Main 6/6 Schematic Diagram

1-8-17

1-8-18

HC4S7SCM6

VPS Schematic Diagram

1-8-19

1-8-20

HC4S7SCV

Function Schematic Diagram

1-8-21

1-8-22

HC4S7SCF

AFV Schematic Diagram

1-8-23

1-8-24

HC4S7SCAFV

Jack Schematic Diagram

1-8-25

1-8-26

HC4S7SCJ

Main CBA Top View

BECAUSE A HOT CHASSIS GROUND IS PRESENT IN THE POWER SUPPLY CIRCUIT , AN ISOLATION TRANSFORMER MUST BE USED. ALSO , IN ORDER TO HAVE THE ABILITY TO INCREASE THE INPUT SLOWLY , WHEN TROUBLESHOOTING THIS TYPE POWER SUPPLY CIRCUIT , A VARIABLE ISOLATION TRANSFORMER IS REQUIRED.

CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE FUSE.

CAUTION ! Fixed voltage power supply circuit is used in this unit. If Main Fuse (F001) is blown, check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply. Otherwise it may cause some components in the power supply circuit to fail.

NOTE : The voltage for parts in hot circuit is measured using hot GND as a common terminal.

Sensor CBA Top View

BHB300F01014-A

BHB300F01014-B

WF1 TP751 V-OUT

TP506 END-S

WF2 TP502 RF-SW

TP507 S-INH

VR501 SW-P

TP501 CTL

WF5 TP301 C-PB

1-8-27

1-8-28

1-8-29

BHC400F01019-A

Main CBA Bottom View

BECAUSE A HOT CHASSIS GROUND IS PRESENT IN THE POWER SUPPLY CIRCUIT , AN ISOLATION TRANSFORMER MUST BE USED. ALSO , IN ORDER TO HAVE THE ABILITY TO INCREASE THE INPUT SLOWLY , WHEN TROUBLESHOOTING THIS TYPE POWER SUPPLY CIRCUIT , A VARIABLE ISOLATION TRANSFORMER IS REQUIRED.

CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD, REPLACE ONLY WITH THE SAME TYPE FUSE.

CAUTION ! Fixed voltage power supply circuit is used in this unit. If Main Fuse (F001) is blown, check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply. Otherwise it may cause some components in the power supply circuit to fail.

NOTE : The voltage for parts in hot circuit is measured using hot GND as a common terminal.

1-8-30

1-8-31

1-8-32

BHC400F01019-A

Function CBA Top View

Function CBA Bottom View

BHC400F01019-B

1-8-33

1-8-34

VPS CBA Top View

VPS CBA Bottom View

BHC400F01019-C

AFV CBA Top View

AFV CBA Bottom View

BHC400F01091

1-8-35

1-8-36

Jack CBA Top View

Jack CBA Bottom View

BHC400F01019-E

1-8-37

1-8-38

WAVEFORMS

WF1

(TP751 of Main CBA)

V-OUT E-E 10usec

50mV x 10

WF1 UPPER

(TP751 of Main CBA) of Main CBA)

WF2 LOWER (TP302

V-OUT RF-SW

0.1V x 10 0.5V x 10 50usec

WF5 UPPER

(TP301 of Main CBA) of Main CBA)

WF2 LOWER (TP302

C-PB RF-SW

10mV x 10 0.5V x 10 5msec

1-9-1

U25WFPAL

WIRING DIAGRAM
FRONT VIDEO IN AUDIO IN (R) AUDIO IN (L) REAR AUDIO OUT (R) AUDIO OUT (L) ANT-IN ANT-OUT CN701 1 2 3 4 5 6 7 8 9 CN1 1 2 3 4 5 6 7 8 9 AC CORD

SENSOR CBA (BHB300F01011)

SENSOR CBA (BHB300F01011)

(DECK ASSEMBLY)
AC HEAD ASSEMBLY
AUDIO ERASE HEAD AUDIO HEAD CONTROL HEAD CL287 AE-H AE-H/FE-H A-COM A-PB/REC CTL(+) CTL(-) CL504 AE-H AE-H/FE-H A-COM A-PB/REC CTL(+) CTL(-)

TU-AUDIO SIF GND TU-AUDIO(R) TU-AUDIO(L) P-ON+5V P-ON+5V IIC BUS-SCL IIC BUS-SDA

AFV CBA (BHC400F01091)

1 2 3 4 5 6

1 2 3 4 5 6

FE HEAD

FULL ERASE HEAD

CL501 2 FE-H 1 FE-H GND

MAIN CBA (BHC400F01019A)

LOADING MOTOR

M

CAPSTAN MOTOR

M
CAPSTAN MOTOR

CYLINDER ASSEMBLY
PG SENSOR

DRUM MOTOR

M

12 11 10 9 8 7 6 5 4 3 2 1

CL502 C-F/R AL+15V/+12V AL+12V P-ON+5V GND C-FG C-CONT GND D-FG LM-FWD/REV D-CONT D-PG

CL151 1 2 3 4 5 6 7 8 9 10 11 12 CL152 1 2 3 4 5 6 7 8 9 10 11

V-OUT1 GND V-IN1 AL+12V(2) NU A-OUT1(R) JK1-8P-OUT A-IN1(L) NU A-IN1(R) GND A-OUT1(L) V-OUT2 GND V-IN2 NU GND A-OUT2(R) SC2-IN A-IN2(L) A-IN2(R) GND A-OUT2(L)

CL101 1 2 3 4 5 6 7 8 9 10 11 12 CL102 1 2 3 4 5 6 7 8 9 10 11

JK101, JK102
1 3 5 2 4 6 8 10 12 14 16 18 20

JACK CBA (BHC400F01019E)

7 9 11 13 15 17 19 21

VIDEO (R)1 HEAD VIDEO (L)1 HEAD VIDEO (L)2 HEAD VIDEO (R)2 HEAD Hi-Fi AUDIO (R) HEAD Hi-Fi AUDIO (L) HEAD 1 2 3 4 5 6 7 8 9 CL253 V(R)-1 V-COM V(L)-1 V(L)-2 V-COM V(R)-2 Hi-Fi-A(R) Hi-Fi-COM Hi-Fi-A(L)

IIC BUS-SCL DAVN-L OSD-V-IN P-ON+5V IIC BUS-SDA FSC-IN(4.43MHz) TUN-SW2

VPS CBA (BHC400F01019C)

CL506 1 KEY-2 2 GND 3 KEY-1

CN652 1 2 3

FUNCTION CBA (BHC400F01019B)

1-10-1

1-10-2

HC4S7WI

IC PIN FUNCTION DESCRIPTIONS
IC501( SERVO / SYSTEM CONTROL IC )
Pin IN/ No. OUT 1 IN Signal Name SC2-IN PGDELAY POWSAF END-S AFC V-ENV KEY-1 KEY-2 LD-SW ST-S N.U. N.U. "H" 4.5V, "L" 1.0V Active Function Level Input Signal from Pin 8 of SCART2 Video Head Switching Pulse Signal Adjusted Voltage P-ON Power Detection Input Signal Tape End Position Detect Signal Automatic Frequency Control Signal Video Envelope Comparator Signal Key Scan Input Signal 1 Key Scan Input Signal 2 Deck Mode Position Detector Signal Tape Start Position Detector Signal Not Used Not Used Dummy V-sync Output L/Hi-z Pin IN/ No. OUT 24 25 26 27 A/D 28 29 30 A/D 31 A/D A/D A/D A/D A/D A/D A/D H/Hi-z L H/L H/L H/L 48 H/L H/L L H/L 1-11-1 HC4S7PIN 49 50 51 52 53 54 IN IN 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 IN SECAMH IN RECSAF-SW Signal Name N.U. N.U. N.U. N.U. N.U. N.U. N.U. Function Not Used Not Used Not Used Not Used Not Used Not Used Not Used Recording Safety SW Detect (With Record tab="L"/With out Record tab="H") SECAM Mode at High Active Level H

2

IN

3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

IN IN IN IN IN IN IN IN -

H/L H L L -

OUT TRICK-H Special Playback = "H" in SECAM Mode IN IN IN IN IN RESET XC-IN Vcc X-IN Vss N.U. N.U. CLKSEL OSCIN System Reset Signal (Reset="L") Sub Clock Sub Clock Vcc Main Clock Input Main Clock Input Vss(GND) Not Used Not Used Clock Select (GND) Clock Input for letter size Clock Output for letter size Not Used LP

OUT XC-OUT

OUT X-OUT

OUT D-VSYNC IN

REMOCO Remote N-IN Control Sensor Color Phase Rotary Changeover SIgnal Video Head Amp Switching Pulse Head Amp Comparator Signal Video Head Switching Pulse HiFi Audio Head Switching Pulse VPS/PDC Data Receive = "L" Not Used Tuner System Control Signal Output Not Used

OUT C-ROTA OUT H-A-SW IN H-ACOMP

OUT OSCOUT N.U. LP

FSC-IN [4.43MHz] 4.43MHz Clock Input OSDVss N.U. OSDVss Not Used Video Signal Output OSDVcc LPF Connected Terminal (Slicer) VIDEO-IN Video Signal Input

OUT RF-SW OUT HiFi-HSW IN OUT DAVN-L N.U. TUNSW2 N.U.

OUT VIDEOOUT OSDVcc HLF

Pin IN/ No. OUT 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 IN IN

Signal Name COLORIN N.U. N.U. C-SYNC

Function SECAM or MESECAM Chroma Video Input Signal at Super Impose Not Used Not Used Composite Synchronized Pulse

Active Level Z/L PULSE H/L L L L/Hi-z H H/L H/L H/L H/L H/L PWM PWM H/L PULSE PULSE H/L/ Hi-z

Pin IN/ No. OUT 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 -

Signal Name N.U.

Function Not Used

Active Level H L L PULSE -

OUT A-MUTE- Audio Mute Control H Signal (Mute = "H") CTL Amp Gain OUT FF/REW- Switching Signal (FF/ L REW="L") IN IN IN IN N.U. Not Used P-DOWN- Power Voltage Down L Detector Signal C-FG AMPVss D-FG D-PG N.U. Capstan Motor Rotation Detection Pulse AMPVss (GND)

OUT 8POUT-1 SCART 1 8Pin Output Control Signal IN N.U. A-MODE N.U. N.U. N.U. Not Used Hi-Fi Tape Detection Signal Not Used Not Used Not Used

Drum Motor Rotation PULSE Detection Pulse Drum Motor Pulse Generator Not Used PULSE H/L H/L PULSE -

OUT D-REC-H Delayed Record Signal COUT POWER- Capstan Power Switching Pulse SW OUT P-ON-H OUT DRVDATA Power On Signal at High LED Clock Driver IC Control Data

AMPVRE V-Ref for CTL AMP FIN C C Terminal Playback/Record Control Signal (-) Playback/Record Control Signal (+) CTL AMP Connected Terminal

IN/ CTL (-) OUT IN/ CTL (+) OUT AMPC

OUT DRV-STB LED Clock Driver IC Chip Select Signal OUT DRV-CLK LED Clock Driver IC Control Clock
2 2 OUT I C BUS- I C BUS Control SCL Clock

CTLAMP To Monitor for CTL out AMP Output AMPVcc AVcc N.U. AMPVcc A/D Converter Power Input/ Standard Voltage Input Not Used

IN/ I2C BUS- 2 I C BUS Control Data OUT SDA N.U. N.U. N.U. Not Used Not Used Not Used Capstan Motor Control Signal Drum Motor Control Signal Capstan Motor FWD/ REV Control Signal (FWD="L"/REV="H") Supply Reel Rotation Signal Take Up Reel Rotation Signal

OUT C-CONT OUT D-CONT OUT C-F/R IN IN S-REEL T-REEL

Notes: Abbreviation for Active Level: PWM -----Pulse Wide Modulation A/D--------Analog - Digital Converter

OUT LM-FWD/ Loading Motor REV Control Signal

1-11-2

HC4S7PIN

LEAD IDENTIFICATIONS
BN1F4M-T BA1F4M-T KTA1266(GR) KTC3199(Y,GR,BL) 2SC2785(J.H.F.K) KRA103M KRC103M KRA104M 2SD1246(S,T) BN1L4M-T KTA1281(Y) 2SC1815-Y(TPE2) 2SC1815-GR(TPE2) 2SC3266-Y (TPE2) 2SC2120-Y(TPE2) KTC3203(Y) 2SC1815-BL(TPE2) 2SA1020(Y) 2SB892(S) KTC3205(Y) 2SA1015-GR(TPE2) PT-6958-FN-TP 28 15

1

14

E C B BR24C02F-W AT24C02N-10SC M24C02-MN6 CAT24WC02JI A 8 5 K 1 4

E C B 80 LTV-817(B.C)-F EL817(A,B,C) 81

LA71750AM-MTB QSZAB0RMB110 51 50

C

E

100 1 30

31

MSP3417G-QG-B8-V3 MSP3417G-QG-B8 33 34 23 22 61

LA72646SM-A-MPB 60 41

40

44 1 PT204-6B-12 MID-32A22 11

12

80

21 1 20 FS1KM-18A FS1KM-14A

LA70100M-TRM 30 16

1

15

C E

G D S

Note: A: Anode K: Cathode E: Emitter C: Collector B: Base R: Reference S: Source G: Gate D: Drain

1-12-1

HC4C7LE

DECK MECHANISM SECTION
VIDEO CASSETTE RECORDER 25C-854

Sec. 2: Deck Mechanism Section
I Standard Maintenance I Alignment for Mechanism I Disassembly/Assembly of Mechanism I Alignment Procedures of Mechanism

TABLE OF CONTENTS
Standard Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1-1 Service Fixtures and Tools. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2-1 Mechanical Alignment Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3-1 Disassembly / Assembly Procedures of Deck Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4-1 Alignment Procedures of Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4-9

STANDARD MAINTENANCE
Service Schedule of Components
H: Hours Deck Ref.No. B2 B3 B8 B27 B31 B573,B574 B37 B52 *B73 B133 B410 B414 B416 B525 Part Name Cylinder Assembly Loading Motor Assembly Pulley Assembly Tension Lever Sub Assembly AC Head Assembly Reel S, Reel T Capstan Motor Cap Belt FE Head Idler Assembly Pinch Arm (A) Assembly M Brake S Assembly M Brake T Assembly LDG Belt I I I I I I I I I I I I I I I I I I I 1,000 H : Check I: Change

Periodic Service Schedule 2,000 H I I I I 3,000 H 4,000 H I

Notes: 1.Clean all parts for the tape transport (Upper Drum with Video Head / Pinch Roller / Audio Control Head / Full Erase Head) using 90% lsopropyl Alcohol. 2.After cleaning the parts, do all DECK ADJUSTMENTS. 3.For the reference numbers listed above, refer to Deck Exploded Views. * B73 ------ Recording Model only

2-1-1

U25MEN

Cleaning
Cleaning of Video Head
Clean the head with a head cleaning stick or chamois cloth. Procedure 1.Remove the top cabinet. 2.Put on a glove (thin type) to avoid touching the upper and lower drum with your bare hand. 3.Put a few drops of 90% Isopropyl alcohol on the head cleaning stick or on the chamois cloth and, by slightly pressing it against the head tip, turn the upper drum to the right and to the left. Notes: 1.The video head surface is made of very hard material, but since it is very thin, avoid cleaning it vertically. 2.Wait for the cleaned part to dry thoroughly before operating the unit. 3.Do not reuse a stained head cleaning stick or a stained chamois cloth.

Cleaning of Audio Control Head
Clean the head with a cotton swab. Procedure 1.Remove the top cabinet. 2.Dip the cotton swab in 90% isopropyl alcohol and clean the audio control head. Be careful not to damage the upper drum and other tape running parts. Notes: 1.Avoid cleaning the audio control head vertically. 2.Wait for the cleaned part to dry thoroughly before operating the unit or damage may occur.

A/C Head

Upper Cylinder Do Not !

Video Head

Cleaning Stick

2-1-2

U25MEN

SERVICE FIXTURE AND TOOLS

J-1-1, J-1-2

J-2

J-3

J-4

J-5

Ref. No. Name J-1-1 J-1-2 Alignment Tape Alignment Tape

Part No. FL6A FL6N8 (1 speed only) FL6NS8 (2 speed only) Available Locally Available Locally Available Locally Available Locally

Adjustment Head Adjustment of Audio Control Head Azimuth and X Value Adjustment of Audio Control Head / Adjustment of Envelope Waveform

J-2 J-3 J-4 J-5

Guide Roller Adj.Screwdriver Mirror Azimuth Adj.Screwdriver + X Value Adj.Screwdriver -

Guide Roller Tape Transportation Check A/C Head Height X Value

2-2-1

U25PFIX

MECHANICAL ALIGNMENT PROCEDURES
Explanation of alignment for the tape to correctly run starts on the next page. Refer to the information below on this page if a tape gets stuck, for example, in the mechanism due to some electrical trouble of the unit. B. Method to place the Cassette Holder in the tapeloaded position without a cassette tape 1. Disconnect the AC Plug. 2. Remove the Top Case and Front Assembly. 3. Turn the LDG Belt in the appropriate direction shown in Fig. M1. Release the locking tabs shown in Fig. M1 and continue turning the LDG Belt until the Cassette Holder comes to the tape-loaded position. Allow a minute or two to complete this task.

Service Information
A. Method for Manual Tape Loading/Unloading To load a cassette tape manually: 1. Disconnect the AC plug. 2. Remove the Top Case and Front Assembly. 3. Insert a cassette tape. Though the tape will not be automatically loaded, make sure that the cassette tape is all the way in at the inlet of the Cassette Holder. To confirm this, lightly push the cassette tape further in and see if the tape comes back out, by a spring motion, just as much as you have pushed in. 4. Turn the LDG Belt in the appropriate direction shown in Fig. M1 for a minute or two to complete this task. To unload a cassette tape manually: 1. Disconnect the AC plug. 2. Remove the Top Case and Front Assembly. 3. Make sure that the Moving guide preparations are in the Eject Position. 4. Turn the LDG Belt in the appropriate direction shown in Fig. M1 until the Moving guide preparations come to the Eject Position. Stop turning when the preparations begin clicking or can not be moved further. However, the tape will be left wound around the cylinder. 5. Turn the LDG Belt in the appropriate direction continuously, and the cassette tape will be ejected. Allow a minute or two to complete this task.

Top View
Moving guide T preparation (Eject Position) Moving guide S preparation (Eject Position) LOAD UNLOAD /EJECT Side View

LDG Belt

Push the tape to load it. Push the locking tab gently to unlock when loading without a cassette.

Fig. M1

Bottom View
LDG Belt (B)

UNLOAD /EJECT

Cam Gear

Fig. M2

2-3-1

U25PALMA

1.Tape Interchangeability Alignment
Note: To do these alignment procedures, make sure that the Tracking Control Circuit is set to the center position every time a tape is loaded or unloaded. (Refer to page 2-3-4, procedure 1-C, step 2.) Equipment required: Dual Trace Oscilloscope VHS Alignment Tape (FL6N8) Guide Roller Adj. Screwdriver X-Value Adj. Screwdriver Note: Before starting this Mechanical Alignment, do all Electrical Adjustment procedures.

Flowchart of Alignment for tape traveling Loading (Use a blank tape.)

Adjust the height of the Guide Rollers (Supply side and take-up side). (Use a blank tape.) (pg. 2-3-3) 1-A Check to see that the tape is not creasing and that there is no slack on the supply and take-up side Guide Rollers. (Use a blank tape.) 1-A Adjust the X Value for maximum envelope. (pg. 2-3-3) (Use Alignment Tape.) 1-B

Not good

Adjust the envelope. (pg. 2-3-4)

1-C
Not good

Check the envelope. OK Adjust the Audio Section. (Azimuth Alignment) (pg. 2-3-4) Check the audio output. OK Check the following: 1. X Value (pg. 2-3-3) 2. Envelope (pg. 2-3-4) OK

1-C

Do the final tape-traveling test to see that the tape runs normally in play mode without creasing or slacking. 1-A OK

1-D
Not good

Completion

1-D

Not good

Adjust the X value and envelope. 1-B, 1-C

1-B, 1-C

2-3-2

U25PALMA

1-A. Preliminary/Final Checking and Alignment of Tape Path
Purpose: To make sure that the tape path is well stabilized. Symptom of Misalignment: If the tape path is unstable, the tape will be damaged. Note: Do not use an Alignment Tape for this procedure. If the unit is not correctly aligned, the tape may be damaged. 1. Playback a blank cassette tape and check to see that the tape runs without creasing at Guide Rollers [2] and [3], and at points A and B on the lead surface. (Refer to Fig M3 and M4.) 2. If creasing is apparent, align the height of the guide rollers by turning the top of Guide Rollers [2] and [3] with a Guide Roller Adj. Screwdriver. (Refer to Fig. M3 and M5.)
Guide Roller [2] Guide Roller [3]

3. Check to see that the tape runs without creasing at Take-up Guide Post [4] or without snaking between Guide Roller [3] and AC Head. (Fig. M3 and M5) 4. If creasing or snaking is apparent, adjust the Tilt Adj. Screw of the AC Head. (Fig. M6)

Azimuth Adj. Screw

AC Head X-Value Adj. Screwdriver

Tilt Adj. Screw

Fig. M6

1-B. X Value Alignment
Purpose: To align the Horizontal Position of the Audio/Control/ Erase Head. Symptom of Misalignment: If the Horizontal Position of the Audio/Control/Erase Head is not properly aligned, maximum envelope cannot be obtained at the Neutral position of the Tracking Control Circuit. 1. Connect the oscilloscope to TP301 (C-PB) and TP501 (CTL) on the Main CBA. Use TP502 (RFSW) as a trigger. 2. Playback the Gray Scale of the Alignment Tape (FL6N8) and confirm that the PB FM signal is present. 3. Set the Tracking Control Circuit to the center position by pressing CH UP button then " PLAY " button on the unit. (Refer to note on bottom of page 2-3-4.)
Lead Surface of Cylinder Tape

AC Head

A

B Take-up Guide Post [4]

Fig. M3

Fig. M4

4. Use the X-Value Adj. Screwdriver so that the PB FM signal at TP301 (C-PB) is maximum. (Fig. M6) 5. Press CH UP button on the unit until the CTL waveform has shifted by approx. +2msec. Make sure that the envelope is simply attenuated (shrinks in height) during this process so that you will know the envelope has been at its peak.

Correct
Guide Roller Tape

Incorrect

Take-up Guide Post Tape

Fig. M5 2-3-3 U25PALMA

6. Press CH DOWN button on the unit until the CTL waveform has shifted from its original position (not the position achieved in step 5, but the position of CTL waveform in step 4) by approximately -2msec. Make sure that the envelope is simply attenuated (shrinks in height) once CTL waveform passes its original position and is further brought in the minus direction. 7. Set the Tracking Control Circuit to the center position by pressing CH UP button and then " PLAY " button.

1-D. Azimuth Alignment of Audio/Control/ Erase Head
Purpose: To correct the Azimuth alignment so that the Audio/ Control/Erase Head meets tape tracks properly. Symptom of Misalignment: If the position of the Audio/Control/Erase Head is not properly aligned, the Audio S/N Ratio or Frequency Response will be poor. 1. Connect the oscilloscope to the audio output jack on the rear side of the deck. 2. Playback the alignment tape (FL6N8) and confirm that the audio signal output level is 8kHz. 3. Adjust Azimuth Adj. Screw so that the output level on the AC Voltmeter or the waveform on the oscilloscope is at maximum. (Fig. M6) Dropping envelope level at the beginning of track.

1-C. Checking/Adjustment of Envelope Waveform
Purpose: To achieve a satisfactory picture and precise tracking. Symptom of Misalignment: If the envelope output is poor, noise will appear in the picture. The tracking will then lose precision and the playback picture will be distorted by any slight variation of the Tracking Control Circuit. 1. Connect the oscilloscope to TP301 (C-PB) on the Main CBA. Use TP502 (RF-SW) as a trigger. 2. Playback the Gray Scale on the Alignment Tape (FL6N8). Set the Tracking Control Circuit to the center position by pressing CH UP button and then " PLAY " button on the unit. Adjust the height of Guide Rollers [2] and [3] (Fig. M3, Page 2-3-3) watching the oscilloscope display so that the envelope becomes as flat as possible. To do this adjustment, turn the top of the Guide Roller with the Guide Roller Adj. Screwdriver. 3. If the envelope is as shown in Fig. M7, adjust the height of Guide Roller [2] (Refer to Fig. M3) so that the waveform looks like the one shown in Fig. M9. 4. If the envelope is as shown in Fig. M8, adjust the height of Guide Roller [3] (Refer to Fig. M3) so that the waveform looks like the one shown in Fig. M9. 5. When Guide Rollers [2] and [3] (Refer to Fig.M3) are aligned properly, there is no envelope drop either at the beginning or end of track as shown in Fig. M9. Note: Upon completion of the adjustment of Guide Rollers [2] and [3] (Refer to Fig. M3), check the X Value by pushing the CH UP or DOWN buttons alternately, to check the symmetry of the envelope. Check the number of pushes to ensure center position. The number of pushes CH UP button to achieve 1/2 level of envelope should match the number of pushes CH DOWN button from center. If required, redo the "X Value Alignment."

Fig. M7 Dropping envelope level at the end of track.

Fig. M8 Envelope is adjusted properly. (No envelope drop)

Fig. M9

2-3-4

U25PALMA

DISASSEMBLY/ASSEMBLY PROCEDURES OF DECK MECHANISM
Before following the procedures described below, be sure to remove the deck assembly from the cabinet. (Refer to CABINET DISASSEMBLY INSTRUCTIONS on page 1-5-1.) All the following procedures, including those for adjustment and replacement of parts, should be done in Eject mode; see the positions of [45] and [46] in Fig.DM1 on page 2-4-3. When reassembling, follow the steps in reverse order. STEP START/LOC. ING No. No. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32] [33] [34] [1] [1] [2] [2] [4] [2] [7] [8] [9] [2] [10] [11] [12] [14] [15] [2] [16] [16] [7],[10] [20] [20] [22] [22] [24] REMOVAL REMOVE/*UNHOOK/ UNLOCK/RELEASE/ UNPLUG/DESOLDER 2(S-1) (S-2) (S-3) (S-4),*(P-1) Desolder, 3(S-5) Desolder, LDG Belt, 2(S-6) (S-7) *(P-2) *(L-1),*(L-2) *(P-3) (S-9) (S-10) (S-11),*(L-3) INSTALLATION ADJUSTMENT CONDITION

PART Guide Holder A Cassette Holder Assembly Slider L Slider R Lock Lever C Plate Cylinder Assembly Loading Motor Assembly AC Head Assembly Tape Guide Assembly Door Opener B Pinch Arm (B) Pinch Arm (A) Assembly FE Head Prism Slider Shaft C Drive Lever L C Drive Lever R Capstan Motor Clutch Assembly(HI) Center Gear Cam Holder F Cam Gear (B) Mode Gear T T T T T T T T T T T T T T T T T T B B B B B B B B B B B B B B B B

Fig. No. DM3 DM4 DM5 DM5 DM5 DM5 DM1,DM6 DM1,DM7 DM1,DM7 DM1,DM8 DM1,DM8 DM1,DM8 DM1,DM8 DM1,DM9 DM1,DM9 DM10 DM10 DM10 DM2,DM11 DM2,DM12 DM12 DM2,DM13 DM2,DM13 DM2,DM14

3(S-12), Cap Belt (C-1) (C-2) (C-3),*(P-4) (C-4)

[20],[23], Mode Lever(HI) [24]

DM2,DM14 (C-5), *(L-4) DM2,DM14 (S-15) DM2,DM14 DM2,DM14 DM2,DM14 (C-6) DM14 DM1,DM14 DM1,DM14 DM1,DM15 *(L-5) DM2,DM15 *(P-5) (+)Refer to Alignment Sec.Pg.2-4-10

[22] [26]

Worm Holder Pulley Assembly

[22],[25] Cam Gear (A) [20] [29] [30] [31] [21],[25] [25] TR Gear C TR Gear Spring TR Gear A/B FF Arm(HI) Idler Assembly(HI) BT Arm

2-4-1

U25PALDA

STEP STARTING /LOC. No. No. [35] [36] [37] [38] [39] [40] [41] [42] [43] [44] [45] [46] [47] [48] [49] [50] [51] (1) [25]

PART

Fig. No. B B T T T T T T T T T T T R R T DM2,DM15 DM2,DM15

REMOVAL REMOVE/*UNHOOK/ UNLOCK/RELEASE/ UNPLUG/DESOLDER

INSTALLATION ADJUSTMENT CONDITION (+)Refer to Alignment Sec.Pg.2-4-9 (+)Refer to Alignment Sec.Pg.2-4-9

Loading Arm S(B) Assembly Loading Arm T(B) [35] Assembly [2],[25] M Brake T(HI) Assembly [2],[25] M Brake S(HI) Assembly Tension Lever Sub [38] Assembly T Lever Holder [39] M Gear(HYT) [2] [2],[15] Sensor Gear [37],[41] Reel T Reel S [39] Moving Guide S [35],[38] Preparation Moving Guide T [36] Preparation [19] TG Post Assembly [18],[28] Rack Assembly [48] [50] [50] (2) F Door Opener Cleaner Lever Assembly CL Post (3)

DM1,DM16 *(P-6) DM1,DM16 *(P-7) DM1,DM16 DM1,DM16 *(L-6) DM1,DM16 (C-7) DM1,DM16 (C-8) DM1,DM16 DM1,DM16 DM1,DM17 DM1,DM17 DM1,DM17 *(L-7) DM18 DM18 DM1,DM6 Type A *(L-8) *(L-9) (6) Type B Type A (7) (+)Refer to Alignment Sec.Pg.2-4-10

T DM6 (5) (4)

(1): Follow steps in sequence. When reassembling, follow the steps in reverse order. These numbers are also used as identification (location) No. of parts in the figures. (2): Indicates the part to start disassembling with in order to disassemble the part in column (1). (3): Name of the part (4): Location of the part: T=Top B=Bottom R=Right L=Left (5): Figure Number (6): Identification of parts to be removed, unhooked, unlocked, released, unplugged, unclamped, or desoldered. P=Spring, W=Washer, C=Cut Washer, S=Screw, *=Unhook, Unlock, Release, Unplug, or Desolder e.g., 2(L-2) = two Locking Tabs (L-2). (7): Adjustment Information for Installation (+):Refer to Deck Exploded Views for lubrication. .

2-4-2

U25PALDA

Top View
[45] [7] [46] [50] [9] [47] [8]

[14] [13] [11] [15] [39] [40] [38] [10] [12] [37]

[44]

[33]

[42]

[31] [32]

[41]

[43]

Fig. DM1

Bottom View

[19]

[36]

[35]

[26] [27]

[24]

[23] [28]

[25]

[22]

[29]

[20]

[34]

Fig. DM2
2-4-3 U25PALDA

(S-1) [1] (S-1)

[3]

[4]

[5] (S-2) [6] (P-1) (S-3) (S-4)

Fig. DM5

Fig. DM3
Type A [7] [50]

Pin D Pin C [2] A
[51] (L-9) Type B [50]

2 Pull up

1 Slide

Pin A Pin B Slot A
(L-8)

Slots B
(S-5)

Slot A First, while pushing the locking tab as shown in the right, slide and pull up the right side on [2] to release Pin A and Pin B from the slots A. Then, remove Pin C and Pin D on [2] from the slots B as shown. Locking tab View for A
A

Fig. DM4

Desolder from bottom View for A

Lead with Blue Stripe

Fig. DM6

2-4-4

U25PALDA

(S-7) [14] [9] [8]

(S-9) (S-10) [15]

A Desolder from bottom [8]

(S-6) LDG Belt
Lead with White Stripe

View for A

Fig. DM7

Fig. DM9

(L-2)

Adj. Screw [11] (L-1)

[17] (L-3)

After removing the Screw (S-11), while pressing the Locking Tab (L-3), remove [16]. [16] [18]

(P-3) [13] [12] [10] (P-2) A

(S-11) Pin of [12] Pin of [10]

Fig. DM10

Grooves of [28] When reassembling [10] and [12], confirm that pin of [10] and pin of [12] are in the grooves of [28] as shown.

[28] View for A

Fig. DM8
2-4-5 U25PALDA

Cap Belt

(C-1) [20]
[19]

[21]

Fig. DM12

(S-12)

Fig. DM11

2-4-6

U25PALDA

[25] (C-3) [23] (S-15) [26] (P-4) [27] (C-6) [29] (L-4) (C-2) [22]

(C-5)

(C-4) [28] [30] [31] [24]

(P-4) [28]

Pin on bottom of [23]

When installing [23], install the spring (P-4) to [28] as shown in the left figure, and then install [23] while pressing the spring (P-4) to the direction of the arrow in the left figure and confirming that the position of the spring (P-4) is placed as shown in the left figure. [23]

[32] Position of Mode Lever when installed Pin of [34] Pin of [37] Pin of [38]

Bottom View

[25]

[28] Top View Align [25] and [28] as shown. First groove on [28] First tooth on [48] [28] When reassembling [28], meet the first groove on [28] to the first tooth on [48] as shown.

Pin on [22]

[28] Top View Position of pin on [22]

Fig. DM14 Fig. DM13

2-4-7

U25PALDA

Refer to the Alignment Section, Page 2-4-9. (P-5) [34] [33] [36] [35]

[45]

[46] [47]

(L-7)

(L-5)

Fig. DM17 Fig. DM15

[39] (C-8) [42] (C-7) (P-7) turn [44] (L-6) [43] [49] [38] [40] turn [37] (P-6) [48] Slide [41]

Fig. DM18

turn

Fig. DM16

2-4-8

U25PALDA

ALIGNMENT PROCEDURES OF MECHANISM
The following procedures describe how to align the individual gears and levers that make up the tape loading/unloading mechanism. Since information about the state of the mechanism is provided to the System Control Circuit only through the Mode Switch, it is essential that the correct relationship between individual gears and levers be maintained. All alignments are to be performed with the mechanism in Eject mode, in the sequence given. Each procedure assumes that all previous procedures have been completed. IMPORTANT: If any one of these alignments is not performed properly, even if off by only one tooth, the unit will unload or stop and it may result in damage to the mechanical or electrical parts.

Alignment 1 Loading Arm, S and T Assembly
Install Loading Arm S and T Assembly so that their triangle marks point to each other as shown in Fig. AL2.

Alignment 2 Mode Gear
Keeping the two triangles pointing at each other, install the Loading Arm T Assembly so that the last tooth of the gear meets the most inside teeth of the Mode Gear. See Fig. AL2.

Alignment 1 Triangle Marks Loading Arm S Assembly Last Tooth

Alignment points in Eject Position
Top View

Alignment 2
Alignment [a]

Loading Arm T Assembly Most inside teeth of Mode Gear

Alignment 3

Mode Gear

Fig. AL2

Alignment [a]
Bottom View Alignment 1

Tape Guide Assembly
Alignment 2

Measurement of the screw must be as specified in Fig. AL3.
Tape Guide Assembly Screw 3.25 ­ 0.1 mm 0.128 ­ 0.004 inch

Alignment [a] can be done independently of any other alignment.

Fig. AL1

This alignment can be done independently of any other alignment.

Fig. AL3

2-4-9

U25NAPM

Alignment 3 Cam Gear (A), Rack Assembly
Install the Rack Assembly so that the first tooth on the gear of the Rack Assembly meets the first groove on the Cam Gear (A) as shown in Fig. AL4.
Top View Cam Gear (A) Alignment 3

First tooth

First groove on the Cam Gear (A)

Gear on Rack Assembly

Fig. AL4

2-4-10

U25NAPM

EXPLODED VIEWS AND PARTS LIST SECTION
VIDEO CASSETTE RECORDER 25C-854

Sec. 3: Exploded views and Parts List Section
I Exploded views I Parts List

TABLE OF CONTENTS
Exploded Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1-1 Mechanical Parts List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2-1 Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3-1 Deck Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4-1

EXPLODED VIEWS
Front Panel

A1X

3-1-1

HC4S7FEX

Cabinet
2L011 2L011 2B18

2L011 A2

2L011

2B9 A5

JACK CBA

2L012
2L022

2L011

2L042 2L022 2L022 2L022 2L041
A4

2L021

2L021 2L021

2B5
2L051

2L021

2L021

SENSOR CBA AFV CBA VPS CBA
2L031 2L041 2B7 2B8 2B46 2B14 2L041

MAIN CBA
2L099 A10

1B1

SENSOR CBA
A3 2B49

FUNCTION CBA
A7

3-1-2

HC4S7CEX

Packing
Some Ref. Numbers are not in sequence.

X1

X20A

X20B

X20C

X3

X2

X10

S7

S2

X4 X6

S3

S2

Unit

A14

S1

3-1-3

HC4S7PEX

DECK EXPLODED VIEWS
Deck Mechanism View 1
Mark B2 Description (Blue grease) Floil G-374G SLIDUS OIL #150

B35 L1467 B9 B10 L1191 B73 B411 B567 B494 B553

L1053

B410 B74

L1051

Chassis Assembly Top View (Lubricating Point) B501

L1450 B12 B11 B492 B37

B560 B426 B121 B126 L1468

L1466

B571

B8

Some Ref. Numbers are not in sequence.

Chassis Assembly Bottom View (Lubricating Point)

3-1-4

U25PALDEX

Deck Mechanism View 2
B587 B27
Note: Both the TENSION LEVER SUB ASSEMBLY MK11(B27) and the TENSION LEVER ASSEMBLY MK11 (B587) can be used.

Mark

Description (Blue grease) Floil G-374G SANKOUL FG84M (Yellow grease)

B508 B487 B573 B518 B499 B414 B585 B564 B572 B565

B574 B148 L1406 B521 B520 B522 B31 B558 B557 B416 B3

B417 B525 B568 B551 B579 B578 B579 B582 View for A B580 B583 A B569
B505

B584

L1151

B133 B488 B581 B507 B491 B570 B502 B513 B516 Bottom Side (Grease point)

B559

Bottom Side (Grease point)

B52

Some Ref. Numbers are not in sequence.

3-1-5

U25PALDEX

Deck Mechanism View 3
Mark L1321 B347 Note: There are two different, but interchangeable types of CLEANER LEVER(B359) in this model, and have different combination with B361. Please see Table 1 for details and combination. (Refer to DECK PARTS LIST section.) Table 1 (B359 and B361 Combination) B359 CLEANER LEVER B361 Type Part No. Part No. A 0VM304413 0VM411114 Not used B 0VM305090 Description (Blue grease) Floil G-374G

L1321

B354 B355

B483 B529 Type B B425 L1461 L1341 B482 B562 L1341 B563 B300 B360 B359

B529 Type A B360 B359

B361

B555

B303 Some Ref. Numbers are not in sequence. B514

3-1-6

U25PALDEX

MECHANICAL PARTS LIST
PRODUCT SAFETY NOTE: Products marked with a ! have special characteristics important to safety. Before replacing any of these components, read carefully the product safety notice in this service manual. Don't degrade the safety of the product through improper servicing. NOTE: Parts that are not assigned part numbers (---------) are not available.
Ref. No. A1X A2 A3 A4 A5 A7 A10! A14 1B1 2B5 2B7 2B8 2B9 2B14 2B18 2B46 2B49 2L011 2L012 2L021 2L022 2L031 2L041 2L042 2L051 2L099 S1 S2 S3 S7 X1 X2 X3 X4 X6 X10! Description FRONT ASSEMBLY HC4S7FD CASE, TOP(ANTHRACITE) HC400EP CHASSIS(PAL-FTZ) HC460ED JACK BOARD(CONV) HC461BD (See Electrical Parts List) JACK BOARD(2-21P) HC460ED (See Electrical Parts List) PANEL, BOTTOM HC460ED LABEL, RATING HC4S7FD LABEL, SERIAL NO. H39H0JD(JPN) or LABEL, BAR CODE HC4S7FD DECK ASSEMBLY CZD011/VM15E0 SHEILD, CYLINDER HC460ED SHIELD ASSEMBLY HC460ED (See Electrical Parts List) BUSH, LED(F) H3700UD (See Electrical Parts List) CUSHION HC460ED CUSHION(PCB) HC460ED FIBER, TOP CASE HC460ED ROHM HOLDER H7770JD (See Electrical Parts List) CHASSIS FIBER HC460ED SCREW, P-TIGHT 3X12 BIND HEAD+ SCREW, P-TIGHT 3X12 BIND HEAD+ SCREW, P-TIGHT M3X10 WASHER HEAD+ SCREW, P-TIGHT M3X10 WASHER HEAD+ (See Electrical Parts List) SCREW, B-TIGHT M3X8 BIND HEAD+ P-TIGHT SCREW 3X8 B