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Models 27MM20BA and 27MMV30B are in the same Solid State Color Television family. The difference between the 27MM20BA and the 27MMV30B is the DDC2B and instruction Book. Please refer to Model 27MM20B and 27MM20BA schematics, assembly, wiring, test, and troubleshooting information when servicing Model 27MMV30B. Refer to Service Manual PA No. 0092 issued in March 1998. Refer to Service Manual PA No. 0092 for the technical information regarding the "Description of Circuit" and "IC's and Transistors Functions" issued in March 1998.

REPLACEMENT

PARTS LIST

This parts list only gives parts which are different from the Service Manual PA No. 0092. PRODUCT SAFETY NOTE: Components marked with aA have special characteristics important to safety. Before replacing any of these components, read carefully, the PRODUCT SAFETY NOTICE of this Service Manual. Do not degrade the safety of the receiver through improper servicing.

For 27MMV30B (Same as 27MM20BA except below parts) SYMBOL NO. N201 B PART NO. QR26891 JK03655(H) DESCRIPTION Instruction Book English PA2 DDC2B P.W.B.

Above parts list of 27MMV30B plus attached replacement parts list are parts which are different from the Service Manual PA No. 0092.

SPECIFICATIONS AND PARTS ARE SUBJECTTO CHANGE FOR IMPROVEMENT

SOLID STATE COLOR TELEVISION
JULY 1998 HHEA-MANUFACTURING DIVISION

PA2
SAFETY PRECAUTIONS
NOTICE: Comply with all cautions and safety-related notes located on or inside the cabinet and on the chassis or picture tube. WARNING: Since the chassis of this receiver is connected to one side of the AC power supply during operation, whenever the receiver is plugged in, service should not be attempted by anyone unfamiliar with the precautions necessary when working on this type of receiver. The following precautions should be observed: 1. Do not install, remove, or handle the picture tube in any manner unless shatterproof goggles are worn. People not so equipped should be kept away from the picture tube while handling. 2. When service is required, an isolation transformer should be inserted between power line and the receiver before any service is performed on a "HOT" chassis receiver. When replacing a chassis in the receiver, all the protective devices must be put back in place, such as nonmetallic knobs, adjustment and barriers, compartment cover-shields, isolation resistors, capacitors, etc. When service is required, observe the original lead dress in the high voltage circuitry area. the manufacturer's replacement Always use components. Critical components as indicated on the circuit diagram should not be replaced by another manufacturer's Furthermore, where a short circuit has occurred, replace those components that indicate evidence of overheating. Before returning a serviced receiver to the customer, the service technician must thoroughly test the unit to be certain that it is completely safe to operate without danger of electrical shock, and be sure that no protective device built into the receiver by the manufacturer has become defective, or inadvertently defeated during servicing. Leakage Current Hot Check Plug the AC line cord directly into a 120V AC 60Hz outlet (do not use an isolation transformer for this check). Turn the AC power ON. Using a Leakage Current Tester (Simpson's Model 229 or equivalent), measure for current from all exposed metal parts of the cabinet (antennas, screwheads, overlays, control shafts, etc.) particularly any exposed metal part having a return path to the chassis or to a known earth ground (water pipe, conduit, etc.). Any current measured must not exceed 0.5 milliamps.

DEVICE UNDER TEST

LEAKAGE CURRENT

(READING SHOULD NOT BE ABOVE 0.5mA)

1 TEST ALL EXPOSED METAL SURFACES

3.

2-WIRE

CORD

4. 5.

fUSlNG AC ADAPTER PLUG AS REQUIRED)

AC LEAKAGE

TEST

6.

ANY MEASUREMENTS NOT WITHIN THE LIMITS OUTLINED ABOVE ARE INDICATIVE OF A POTENTIAL SHOCK HAZARD AND MUST BE RETURNING THE CORRECTED BEFORE RECEIVER TO THE CUSTOMER. High Voltage This receiver is provided with a hold down circuit for clearly indicating that voltage has increased in excess of a predetermined value. Comply with all notes described in this service manual regarding this hold down circuit when servicing, so that this hold down circuit is operated correctly. Serviceman Warning With minimum BRIGHTNESS and CONTRAST, the operating high voltage in this receiver is lower than 34.0kV. In case any component having influence on the high voltage is replaced, confirm that high voltage with minimum BRIGHTNESS and CONTRAST is lower than 34.0kV. To measure high voltage use a High Impedance High Voltage meter. Connect (-) to chassis earth and (+) to the CRT Anode button. (See the following connection diagram). NOTE: Turn power switch OFF without fail before the connection to the Anode button is made.

Therefore, the following checks should be performed for the continued protection of the customer and service technician. Leakage Current Cold Check With the AC plug removed from the 12OV AC 60Hz source, place a jumper across the two plug prongs. Using an insulation tester (DC500V), connect one lead to the jumpered AC plug and touch the other lead to each exposed metal part (antennas, screwheads, metal overlays, control shafts, etc.), particularly any exposed metal part having a return path to the chassis should have a minimum resistor reading of 0.24MQ and a maximum resistor reading of 12MR . Any resistance value below or above this range indicates an abnormality which requires corrective action. An exposed metal part having a return path to the chassis will indicate an open circuit. 2

I
PRODUCT SAFETY NOTICE
Many electrical and mechanical parts in HITACHI television receivers have special safety-related characteristics. These are often not evident from visual inspection nor can the protection afforded by them necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this Service Manual. Electrical components having such features are identified with an a mark in the schematics and parts list in this Service Manual. The use of a substitute replacement component does not have the same safety characteristics HITACHI-recommended replacement component, in the parts list in this Service Manual, may create fire, X-Radiation, or other hazards. which as the shown shock,

?A2

This Service Manual is intended for qualified service technicians; it is not meant for the casual do-it-yourselfer. Qualified technicians have the necessary test equipment and tools, and have been trained to properly and safely repair complex products such as those covered by this manual. Improperly performed repairs can adversely affect the safety and reliability of the product and may void warranty. Consumers should not risk trying to do the necessary repairs and should refer to a qualified service technician. WARNING Lead in solder used in this product is listed by the California Health and Welfare agency as a known reproductive toxicant which may cause birth defects or other reproductive harm (California Health and Safety Code, Section 25249.5). When servicing or handling circuit boards and other components which contain lead in solder, avoid unprotected skin contact with solder. Also, when soldering do not inhale any smoke or fumes produced.

Production safety is continuously under review and new instructions are issued from time to time. For the latest information, always consult the current HITACHI Service Manual. A subscription to, or additional copies of HITACHI Service Manuals may be obtained at a nominal charge from HITACHI Sales Corporation.
CPT ANODE \

SAFETY NOTICE USE ISOLATION TRANSFORMER WHEN SERVICING
Components having special safety characteristics identified by aon the parts list in this Model service manual and its supplements and bulletins. Before servicing this, it is important that the service technician read and follow the "Safety Precautions" and the "Product Safety Notices" in this Service Manual. For continued X-Radiation protection, replace picture tube with original type or HITACHI equivalent type.

CPT

\

CHASSIS

GROUND

X-Radiation TUBE: The primary source of X-Radiation in this receiver is the picture tube. The tube utilized in this chassis is specially constructed to limit X-Radiation emissions. For continued X-Radiation protection, the replacement tube must be the same type as the original HITACHI-approved type. When troubleshooting and making test measurements in a receiver with an excessive high voltage problem, avoid being unnecessarily close to the picture tube and the high voltage component. Do not operate the chassis longer than is necessary to locate the cause of excessive voltage.

POWER SOURCE
This television receiver is designed to operate on 120 Volts/ 60H2, AC house current. Insert the power cord into a 120 Volts/GOHz outlet.
NEVER CONNECT SPECIFIED VOLTAGE THE TV TO OTHER THAN OR TO DIRECT CURRENT. THE

3

TECHNICAL
27MMV30B/PA2 PICTURE TUBE . . . . . . . . . . . . . . . . .A68KSA30X(D)

SPECIFICATIONS

CAUTION The following symbol near the fuse indicates fast operating fuse (to be replaced). Fuse ratings appear within the symbol. "RISK OF FIRE - REPLACE FUSE AS MARKED" Example:

F901

-VGA SPECIFICATONS
1 TYPE
MODE

The rating of fuse F901 is 6.OA-125V. Replace with the same type fuse for continued protection against fire.

1

PS2-1 640X350

1

Ps2-2 640X400 31.469Khz

1

PS2-3 640X480

i

Inputs: l Power Input .................. AC 12OV, 60Hz l Power Consumption (operating) .......... 188 W l Power Consumption (maximum). ......... 188 W . Antenna input impedance. ............ Channel coverage. ................... l VHF-Band .......................... l UHF-Band ......................... l CATV Mid Band. ...................
l l l l

HORIZONTAL FREQUENCY 1 F;E;;&y SYNC TYPE 1

31.469Khz 70.06Hz HN separate TTL: positive TTL: negative 1

31.469Khz 1 59.94Hz HN separate TTL: negative TTL: negative 1

70.06Hz HN separate TTL: negative TTL: positive

.75 Ohm 181 ch. .2- 13 14 - 69 A-5 - A-l J-W W+l - W+28 W+29 - W+84 1 .OVp-p, 75 Ohm

I

SYNC

H V

PoLAR'TY

Super Band ........................... Hyper Band. .................... Ultra Band. ....................

D-Sub Mini 15Pin Connector Pin ,Assignments

. Video input. ................. S-Video input Luminance (Y) ............... Chrominance (C) ........... l Audio input level (average)
l

1 .OVp-p, 75 Ohm 0.286Vp-p, 75 Ohm . .400mVrms, 47K Ohm

PIN NO. 1

SIGNAL Red Video Green Video

PIN NO. 9

SIGNAL No Connection Ground No Connection No Connection H-S nc (or Hd sync) V-Sync Ground

outputs: l Audio Output (variable) ...... Dimensions: l Height (in.) l Width (in.) l Depth (in.) l Weight (Ibs.)

2

10
11 12 13 14

400mVrms,

1K Ohm

3 4

Blue Video Ground Ground Red Ground

23 `l32 27 9/32 20 `3/64 88

5 6 7 8

Green Ground
Blue Ground

15

NOTE: Due to improvements,

specifications

in this operating

guide are subject to change

without

notice.

I

4

TECHNICAL
HV Protection Hiah voltaae Adjustment circuit operation checking.

CAUTIONS

limiter circuit operation Preparation

check and over voltaae

protection

circuit operation

check.

(1) Connect a high voltage voltmeter between CPT anode terminal (Anode cap side) and the ground as below. (2) Set AC input voltage to 120&3V. (3) Receive Hitachi circle pattern and set "Bright" and "CONTRAST" to max. Adjust Screen VR so that Beam Current is 1 B 1 .15&O. 1 mA. (The voltage of ABL terminal-C725 both ends should be 12V or less)

CPT

\

High voltage voltmeter (DC voltage

divider)

ital GND WIRE

voltmeter

Use the voltmeter Of input impedencelOM ohm or more with indication to the 1st decimal place.

3 w
c725 0.1150

Less than 12V

Adiustment

Procedure

(1) Check that the normal High Voltage is 27.0+1.5KV and +B Voltage is 130+1.5V. (2) Connect jig A to the Both end of R706 and check that the power is turned off.

D706 +56V 0-w To D718

4-s-J
jig=kR 1/8W

(3) Disconnect the AC plug and remove jig A.

1 /XN&S;`ELATORY

1

Federal Communications Commission Notice
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
l l l l

Reorient Increase Connect Consult

or relocate the receiving antenna. the separation between the equipment and the receiver. the equipment into an outlet on a circuit different from that to which the receiver is connected. the dealer or an experienced radio or television technician for help.

Modifications
The FCC requires the user to be notified that any changes or modifications made to this device that are not expressly approved by Hitachi Home Electronics (America), Inc. may void the user's authority to operate the equipment.

Cables
Connections to this device must be made with shielded cables with metallic RFI/EMI connector hoods to maintain compliance with FCC Rules and Regulations. Any cables that are supplied with the system must be replaced with identical cables in order to assure compliance with FCC rules. Order Hitachi spares as replacement cables.

Declaration of Conformity
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. Any cables that are supplied with the system must be replaced with identical cables in order to assure compliance with FCC rules. Order Hitachi spares as replacement cables. For questions regarding this declaration, Hitachi Home Electronics (America), 1855 Dornoch Court San Diego, CA 92173 l-800-448-2244 (l -800-HITACHI) Attn: Customer Relations Inc. contact:

REPLACEMENT

PARTS LIST

PRODUCT SAFETY NOTE: Components marked with aAhave special characters important to safety. Before replacing any of these components, read carefully the PRODUCT SAFETY NOTICE of this service manual. Don't degrade the safety of the receiver through improper servicing.
ABBREVIATIONS Capacitors: Ceramic Polyester Electrolytic Polypropylene Paper Tantalum Trimmer Mvkr Resistor: Carbon Film Carbon Variable Wire Fuse Composition Film Resistor Metal Oxide Wound Resistor Semiconductors: TR: DI: ZD: VA: TH: IC: Transistor Diode Zener Varistor Thermistor Integrated Circuit Diode

CD: PF: EL: PP: PR: TA: TM:
MC

Disc Film

CF: cc: MF: VR: WW: FR: MG:

Metal Glaze

SYMBOL
NO.

PART DESCRIPTION

DDCPB P.W.B. LJT0660 CYOI CYO2 DYOl DY02 DY03 IYOl KY51 KY52 LYOI PYOl PYO2 RYOl RY02 RY03 RY04 RY05

0880009R 0800039R 2339856M 2339856M 2339856M CPOlO42U 2974432M 2974432M BH00697R 2959051 0100041 M 0100041 M 0100041 M 0700063M 0700063M

CAP.-POLYESTER 0.01 UF-K 50V CAP.-ELECTRO. 47UF-M 1OV ZENER HZS7B3 TA ZENER HZS7B3 TA ZENER HZS783 TA DIGITAL MONOLITHIC IC (24LC21AJP) JUMPER WIRE (0.5 L=52MM) JUMPER WIRE (0.5 L=52MM) COIL 1OOUH 5P POST PIN 4P TYPE PH PIN POST (PH 2P) RES.-CARBON FLM 1/8W 1 00-JB RES.-CARBON FLM 1/8W 1 00-JB RES.-CARBON FLM 1/8W 1 00-JB RES.-CARBON FLM 1/16W 47K-JB RES.-CARBON FLM 1/16W 47K-JB

7

BASIC CIRCUIT DIAGRAM DDC2B Circuit Schematic

lpyoll
GND Data CLK X-Sync

HZS7B3

-lhl DYOI HZS7B3

lpvoll
+5v +5v

I

nil DY02 HZS783

nh DY03 HZS7B3

-vv--

-..__ "103

.__ ~o,,BJ I"",

I

RYOS 47K

II

a'
2

LYOI 100

I PA2CHASSISBLOCK DIAGRAM
PRODUCT SAFETY NOTE: Components marked with a A and shaded have special characteristics important to safety. Before replacing any of these components, read carrefully the PRODUCT SAFETY NOTICE of this Service Manual. Don't degrade the safety of the receiver through improper servicing.
l

l

All DC voltage to be measured with a tester (100kWV). Voltage taken on a complex color bar signal including a standard color bar signal. Since this is a basic circuit diagram, the value of the parts is subject to be altered for improvement.

8

NOTES:

HITACHI