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S/M No. :DSJ112FEFO
Service Manual
REAR PROJECTION TV
CHASSIS : SJ-112
MODEL : DSJ-4710CRA/5510CRA
DSJ-4720CRA/5520CRA
Caution
: In this Manual, some parts can be changed for improving. their
performance without notice in the parts list. So, if you need the
latest parts information, please refer to PPL(Parts Price List)in
Service Information Center(http://svc.dwe.co.kr)
DAEWOO ELECTRONICS Corp.
http : //svc.dwe.co.kr Feb. 2004
Contents
1. Safety Instruction 3
2. Product Specification 4
3. Remote Control 5
4. Adjusting Method 6
5. Explanation for circuit operation 12
6. Trouble Shooting 34
7. Service Part list 43
8. Schematic Diagram
1) Block Diagram 76
2) Power 77
3) Rear IO 78
4) AV main 79
5) deflection 80
6) Convergence Amp & Sound Amp 81
7) Convergence Module 82
8) CRT Amp 83
9) Control & side 84
9. PRINTED CIRCUIT BOARD
1) Main PCB 85
2) Power PCB 86
3) AMP PCB 87
4) CRT PCB 88
5) DEF PCB 89
6) UNION-1 PCB(CONTROL, SIDE) 90
7) UNION-2 PCB(CONV MODULE, REAR IO 91
10. EXPLODED VIEW
1) DSJ-4710 92
2) DSJ-4720 93
3) DSJ-5510 94
4) DSJ-5520 95
1
1. Safety Instruction
1. When all services are carried out, every item required in this manual needs to be followed
and the services should be performed by A/S man.
2. The following general items should be performed before staring the services.
1) Unplug the power.
2) Uncover the cabinet.
3) To prevent a danger of shock, touch a terminal of plug on the chassis ground and discharge
a remaining voltage.
4) Check if all parts are in the proper places, omitted or burned.
5) Check the soldering state of all parts, if a clad copper is loose or peeled off and if there is a
short between clad coppers.
6) When all the articles mentioned above are normal, plug the power and refer to "Fault
diagnosis according to cause and symptom" of this manual for service according to screen
state.
3. Pay attention to a basic wiring and check a damaged part if a disconnected circuit is found
and replace it with a new one.
4. The equal rated parts should be used depending on the parts list of this manual when a part
needs to be replaced. Because some electronic parts and appliances have safety-related
features, an electric shock, file or X-RAY radiation can be caused if no equal rated parts are
used.
5. When a part needs to be replaced and soldered on PCB, the part should be inserted in the
right position and not contact with even a terminal of other part.
Especially, a high voltage resistance should be inserted with 10mm away from the PCB.
6. Since approx. 30KV high voltage is applied to the Braun tube in operating the TV set, a little
X-RAY can be radiated. If the voltage is too high, harmful X-RAY can result in a danger.
Therefore, A/S man with sufficient knowledge about high voltage needs to perform the
service. Especially, be sure to discharge the anode of the Braun tube on the chassis ground
of TV set before starting the repair.
7. Examine the followings before finishing the service.
1) Check if all protecting components have been assembled.
2) Keep the lead line away from high voltage or high temperature parts and check if all wires
have been connected.
3) Check a leakage current to protect a user from a shock.
Observances for safe service
2
8. How to check a leakage current
1) Plug the power directly.
2) After connecting 1.5V 10W resistance and 0.15uF condenser in a row, link one with an
exposed metal part of TV set and earth the other (proper earth place such as water pipe).
9. A couple persons or more should perform the repair.
When a back cover needs to be separated, pull it out about half and remove the power cord
before complete uncovering.
10. Remove the anode cable which is fixed at HVG in separating the anode cable from HVG or
replacing CRT or HVG. Because a high voltage charged in the anode isn't discharged
completely even though the AC power cord is removed, the high voltage can be sent to TV
set via the power cord and cause its damage.
Therefore, be sure to observe the following method in replacing a high voltage cable.
1) How to remove a high voltage cable
a. Make a discharger to discharge a high voltage.
b. Remove the power cord and wait for 30 sec.
c. Remove the anode cable after discharging as the method mentioned below.
2) How to produce
a. Solder MW resistance and clip lead.
b. Place the soldered part on a driver to tap.
3) How to discharge
a. Connect the clip with CRT NET GND.
b. Pull upward the anode cable slightly, giving a proper force to both nippers of the high
voltage plug locked in HVG. Then, the HVG is removed from the high voltage cable. Be
careful not to destroying the HVG plug socket which connects the high voltage plugs by
giving an excessive force to the nippers in the course.
c. To discharge a high voltage, contact the discharger with a peeled wire at the end of the
anode cable which is removed from HVG.
d. When separating the high voltage plug from the high voltage cable, put both tips of a
pincette in the plug and pull the plug to the end of the high voltage cable.
3
2. Specifications
Input voltage AC 220V, 60Hz
Power consumption 230watts
Dimensions (W x H x D) 1278 x 1351.7 x 586mm (5510)
1278 x 1351.7 x 591mm (5520)
General 1110 x 1210 x 532.5mm (4710)
1110 x 1210 x 529.5mm (4720)
Weight 77.9Kg(55"), 66.5Kg(47")
Antenna input One 75 ohm external input terminal
for UHF/VHF/Cable
Screen size 139cm(55"),119cm(47"), 16:9 Aspect Ratio
Scanning type DTV : 1080I @ 33.75KHz
Image NTSC/DVD: 480p @ 31.5KHz
1080I @ 33.75KHz
CRT size 7"
Sound system 3D Stereophonic sound
NTSC voice Stereo, Sound multiplex
Voice
Voice output 15W/ch (Main L/R)
Rear
Antenna input 2EA
NTSC AV input 2pairs (S-Video/Video/L/R)
External NTSC AV monitor output 1pair(Video/L/R)
Input/ Component input 2pair(Y/Pb/Pr)
Output Right
NTSC AV input 1pairs(S-Video/Video/L/R)
4
3. Specifications of remote control
DISPLAY Power
TV/VCR/CATV
Channel number (0-9)
Use to select channel directly 0~9
100 Prev
Use it when selecting a channel It returns to previous channel.
number of over 100
MENU
Use it to make picture adjustment,
screen format, sound adjustment,
TV/Component
input selection, and utilities. TV -> Component 1 -> Component 2 -> TV
TV/VIDEO
Use this function to make
video input selection. CH
It changes in the following sequence
TV -> VIDEO1 -> 2 -> 3 -> TV
VOLUME
Mute
Dolby Virtual
CHANNEL ADD/ERASE Sound Mode
This feature either memorizes the This feature allows you to choose the mode ,
current channel or erases a channel Each time the button is pressed, it rotates from
that has previously memorized. Normal -> Music -> Movie -> News -> User.
Sleep Timer Bilingual Broadcasting
This feature is used to set up the time This feature allows you to select the
of automatic turn off. language while broadcasting.
Screen Size VCR Function
This feature converts the screen size by REW, PLAY, FF, STOP, REC, PAUSE
changing its aspect ratio. Each time you Caption
press the button, it will be changed from This feature allows you to choose the
16:9 -> 4:3 -> Panorama -> ZOOM1 caption.
->ZOOM2 Each time the button is pressed it rotates
from CC1 -> CC2 -> CC3 -> CC4 -> Off
Auto Picture ANT
Standard -> Cinema -> Dynamic -> User
PIP
PIP
Search
TV/Video STILL
Position SWAP
5
4. Adjusting Method
Adjustment of temporary ITC
Step 1. Temporary fixation of DY
1) Insert DY in R, G, B CRT and tighten the screws properly with DY pushed upward to the end
(Refer to Figure 1)
2) Adjust the slant and position of DY so that the rectangle projections of DY are shown in front
of the set.
DY rectangle GENTERING VM COIL
projection MAGNET
(Figure 1. Front part of CRT assembly)
Step 2. Fixation of VM coil
1) Tighten the screw completely with R, G, B, VM coil pushed upward to the end (Refer to
Figure 1)
Applied chassis and model:SJ-111, 112/DSJ-5510(20),DSJ-4710(20)
6
Adjusting Method
Completion of control
- All adjustments need to be performed after heat-run for 30 min or more.
- Heat-run is executed in the state of non-signal noise.
- If a retrace line appears on the screen during heat-run, rotate the screen VR left and carry out
heat-run when it disappears.
- Note) If stop image is kept over 10 min, a fluorescent material of CRT can be damaged.
Step 1. Control of screen voltage
1) Select `Video 1' without a signal.
2) After turning the screen VR of focus pack right, slowly rotate it left when a retrace line
appears and fix it when the line disappears completely.
3) Control Red VR, Green VR and Blue VR in the order.
4) Fix the VR by lock paint after the control is completed.
Note) This control should be performed in a darkroom.
SCREEN(R/G/B)
FOCUS(R/G/B)
[Figure 2. Exterior view of focus-pack]
Step 2. Control of P-Lens focus
1) Receive RETMA pattern.
2) Loose the fixing nut of lens.
3) Rotate the fixing nut of lens left and then right slowly. Fix the optimum focus position by
repeating this method.
Note 1) Control the focus on the basis of 6cm by 6cm (intra-office signal 8CH, No.3) at the
left bottom of the screen.
Note 2) Perform the focus readjustment or correction if the entire screen isn't focused even
after the completion of focus control.
Applied chassis and model:SJ-111, 112/DSJ-5510(20),DSJ-4710(20)
7
Adjusting Method
4) When the focus control is finished, apply a silicon bond between inside and outside
diameter, paying attention so that the lens isn't moved.
5) Project R, G, B signal only by one signal, using a lens cover and control G, R and B in the
order.
Note) This control should be performed in a darkroom. Especially, be careful not to touch the
lens with a hand.
Step 3. Focus control
1) Receive RETMA pattern.
2) Rotate the focus-pack of focus VR right and left to fix the optimum focus.
Note 1) Control the focus on the basis of 6cm by 6cm (intra-office signal 8CH, No.3) at the
left bottom of the screen.
Note 2) Perform the focus readjustment or correction if the entire screen isn't focused even
after the completion of focus control.
3) Project R, G, B signal only by one color, using a lens cover and control G, R and B in the
order.
Step 4. Control of G-CRT 2-pole, 4-pole magnet
1) Receive DOT pattern.
2) Have only a green screen appear, using a lens cover.
3) Adjust the core to be located in the center of DOT, using a 4-pole magnet.
4) Adjust the DOT to be circular, using a 2-pole magnet.
5) Tighten the fixing part so that the magnet can't move after finishing the adjustment.
Note 1) This control should be performed in a darkroom.
Note 2) Perform the focus readjustment or correction if the entire screen isn't focused even
after the completion of focus control.
Applied chassis and model:SJ-111, 112/DSJ-5510(20),DSJ-4710(20)
8
Adjusting Method
Step 5. Control of deflection yoke and tilt
1) Receive CROSS-HATCH pattern.
2) Rotating a loose DY left and right, control it so that the horizon of R, G, and B can be
projected on to the screen correctly in the form of horizon. (Refer to the center point of
Front -Mask)
3)After adjusting the R, G, B, FY, fix the DY with a lever not to turn.
Step 6. Control of raster position
1) Receive CROSS-HATCH pattern.
2) Adjusting the centering magnet attached to the DY, locate the center of green image at the
center of the screen (Refer to Figure 1).
3) Adjusting the centering magnet of R and B, locate R left and B right on the basis of G in the
center.
4) Fit the horizon in the center of R and B to the horizon of G.
5) In the center of screen, locate the vertical line of R approx. 20 to 30mm to the left on the
basis of G and the vertical line of G approx.20 to 30mm to the right (Refer to Figure 4).
Figure 4. Control of R, G, B raster
Step 7. Control of convergence
a. Control of 480i convergence
1) Input the signal of auto alignment system in a component terminal.
(Select one between component 1 and 2.)
Applied chassis and model:SJ-111, 112/DSJ-5510(20),DSJ-4710(20)
9
Adjusting Method
2) Connect I2C line of the auto alignment system with housing (P503) at the top of a
convergence board.
3) Select CONV.EXE in the auto alignment system program and press ENTER.
4) Control the user convergence with a remote control after the control is finished.
b. Control of 1080i convergence
1) Repeat the above 1) to 4) for 1080i mode.
Step 8. Control of white balance
1) Connect a control pattern (intra-office signal cable broadcasting 32 CH) with external input 3.
2) Select the screen mode as standard.
3) Locate the sensor of 3298 system at the center of High/Low Beam.
4) Execute the projection program of control PC.
5) When OSD of `OK' appears on the monitor of control PC, the control is completed.
Measuring unit: Multimedia Display Tester 3298(YOKOGAYA)
Measuring signal: White -Balance Control Pattern (Intra-office signal cable broadcasting
32CH)
Coordinates setup:x=0.275 0.005 / y=0.275 0.005
Initial data (S8)
R DRV : 31 (RED DRIVE)
G DRV : 40 (GREEN DRIVE)
B DRV : 31 (BLUE DRIVE)
R CUT : 61 (RED BIAS)
G CUT : 64 (GREEN BIAS)
B CUT : 61 (BLUE BIAS)
Applied chassis and model:SJ-111, 112/DSJ-5510(20),DSJ-4710(20)
10
Adjusting Method
Step 9.
Control of 480p color accord
1) Receive Cross-Hatch 480p signal by using HD signal output instrument.
2) Press the S7 key of service remote control to enter the 480p color accord control mode.
3) Change RHLIN to control RED color accord.
4) Change BHLIN to control BLUE color accord.
Measuring unit:VG-858(ASTRO)
Initial data (S7)
RH LIN : -53
BH LIN : +127
Step 10.
Control of sub brightness
- Press the S9 key to enter the Sub Brightness control mode.
- Screen mode: Standard
1) Receive RETMA pattern (intra-office signal cable broadcasting 96 CH)
2) Press the S9 key.
3) Control the Sub Brightness so that 18% gradation can be identified in the contrast chart of
gradation pattern.
Applied chassis and model:SJ-111, 112/DSJ-5510(20),DSJ-4710(20)
11
5. Explanation for circuit operation
< Contents >
1. Specifications and Features
1-1 Specifications of product
1-2 Features of product
2. Power
2-1 Outline
2-2 Block diagram
2-3 Composition of power supply
2-4 Explanation for power supply operation
3. Deflection
3-1 Outline
3-2 Block diagram
3-3 Composition of deflection part
3-4 Explanation for operation
4. Video signal processing
4-1 Block diagram
4-2 Video processor
5. Sound
5-1 Switching part
5-2 Sound processing
6. Convergence
6-1 Outline
6-2 Block diagram
6-3 Composition
7. CRT AMP
12
Explanation for circuit operation
1. Specification/Feature
1-1. Specification of prodict
Input voltage AC 220V, 60Hz
Power consumption 230watts
Dimensions (W x H x D) 1278 x 1351.7 x 586mm (5510)
1278 x 1351.7 x 591mm (5520)
1110 x 1210 x 532.5mm (4710)
General 1110 x 1210 x 529.5mm (4720)
Weight 77.9Kg(55"), 66.5Kg(47")
Antenna input One 75 ohm external input terminal
for UHF/VHF/Cable
Screen size 139cm(55"),119cm(47"), 16:9 Aspect Ratio
Scanning type DTV : 1080I @ 33.75KHz
NTSC/DVD: 480p @ 31.5KHz
Image
1080I @ 33.75KHz
CRT size 7"
Sound system 3D Stereophonic sound
NTSC voice Stereo, Sound multiplex
Voice
Voice output 15W/ch (Main L/R)
Rear
Antenna input 2EA
NTSC AV input 2pairs (S-Video/Video/L/R)
External
NTSC AV monitor output 1pair(Video/L/R)
Input/
Component input 2pair(Y/Pb/Pr)
Output
Right
NTSC AV input 1pairs(S-Video/Video/L/R)
1-2. Features of product
7" Pure Flat Picture Tube
Digital 3D Comb Filter
Video Noise Reduction
1080i(HD), Line doubled to 480p(NTSC)
Velocity Modulation Scanning
Dynamic Focus System
Auto channel Programming
Black Level Expender
13
Explanation for circuit operation
2. Power
2-1. Outline
This power is a power supply of 230W to provide a power for 55"/47"CRT Projection TV.
2-2. Block diagram
The block diagram of this power is as follows.
2-3 Composition of power supply
This power supply is formed in Fly-back type to provide various powers.
The design specification of this power supply is as follows.
1) Input power: 120Vac (+/- 10%), 60Hz
2) Power consumption : 230W
3) The second power supply is shown in table 1-1. (Final power supply)
14
Explanation for circuit operation
No. Position Kind Purpose Current Remark
The second power supply
No. Position Kind Purpose Current Remark
1 T802 200V CRT AMP B+ 80mA
2 T802 135V HIGH VOLTAGE B+ 900mA F/B LINE
3 T802 12V GENERAL PURPOSE 600mA
4 T802 9V GENERAL PURPOSE 1000mA
5 T802 5V GENERAL PURPOSE 400mA
6 T802 5V GENERAL PURPOSE 750mA
7 T802 6.3V HEATER B+ 650mA
8 T803 +25V SUB-DY AMP B+ 900mA F/B LINE
9 T803 -25V SUB-DY AMP B+ 900mA
10 T803 30V GENERAL PURPOSE 100mA
11 T803 +7.5V GENERAL PURPOSE 100mA
12 T803 -12V GENERAL PURPOSE 300mA
13 T803 +15V AUDIO AMP B+ 2000mA
14 T803 -15V AUDIO AMP B+ 2000mA
15 T801 5V STAND-BY B+ 500mA
< TABLE 1-1 > The second power supply
2-4 Explanation for power supply operation
1) Power supply and STAND-BY power
The voltage via a bipolarity power code (PC801) goes through a line filter area composed of
EMI filter (L801, L802, L827), X-capacitor (C801, C802, C803) and Y-capacitor (C804,
C805), is rectified and smoothed (C-806) in bridge diode (D801 -D804).
This voltage provides a power for STAND-BY trans (T-801) and TOP232P of STAND-BY
power IC (I801) and the second TRANS supplies a STAND-BY power for U-COM.
2) Main power start
When the U-COM supplies a PWR SWITCH ON signal for Q801 base via PA802 connector, a
positive terminal relay (RLY1) starts and AC power is rectified and smoothed (C809, C816) in
a bridge diode (D-808) via a Y-capacitor (C-811, C812).
The voltage before smoothing supplies a starting voltage for No.4 terminal of STR-F6656
(I802, I803) via (R809+R817) and (R823+R824).
When STR-F6656 starts, the voltage via a coil bead (L825, L826) goes to coil P of trans and
then to drain (Pin No.3) of internal power MOSFET of STR-F6655. The voltage flowing in coil
D supplies a power for terminal No.4 of trans STR-F6656.
Then, a current flows via R813 and R818 without going through (R809+R817) and
(R823+R824). That is, (R809+R817) and (R823+R824) supplies a current only at starting.
3) Specification of STR-F6656
The STR-F6656 is a power MOSFET and control IC built-in Fly-back type of Hybrid IC for
switching power.
The feature of this IC is a Quasi-Resonance associated operation IC that the number of parts
added to external is small, various protection functions (protection from overcurrent,
overvoltage and overheat) are offered and a power loss decreases by lowering an originating
frequency at STABD-BY.
15
Explanation for circuit operation
The detailed specifications of this IC are as follows.
Terminal No. Symbol Name Functions
1 O. Overcurrent/Feedback terminal Overcurrent detection signal
C.
P./
F.
B
2 S Source terminal MSOFET source
3 D Drain terminal MOSFET drain
4 Vin Power terminal Control circuit power input
5 GND Ground terminal Ground
Symbol Functions
O.V.P Overvoltage protection circuit built-in
T.S.D Overheat protection circuit built-in
Specifications Condition for
Item Terminal Symbol Unit
MAX TYP MAX measuring
Operation start power voltage 4 - 5 VIN(ON) 14.4 16 17.6 V
Operation stop power voltage 4 - 5 VIN(OFF) 9 10 11 V
Circuit current at operation 4 - 5 IIN(ON) - - 30 mA
Circuit current at non-operation4 - 5 IIN(OFF) - - 100 -
Maximum OFF time - TOFF(MAX) 45 - 55 SEC
Minimum Quasi-Resonance 1 - 5 Tth(2) - - 1.0 SEC
signal input time
Minimum OFF time - TOFF(MIN) - - 1.5 SEC SEC
OOP/FB terminal threshold voltage 1 - 5 Vth(1) 0.68 0.73 0.78 V -
OOP/FB terminal threshold voltage 2 1 - 5 Vth(2) 1.3 1.45 1.6 V
OOP/FB terminal outflow current 1-5 IOCP/FB 1.2 1.35 1.5 mA
OVP operating power voltage 4 - 5 VIN(OVP) 20.5 22.5 24.5 V -
Latch circuit sustaining current 4 - 5 IIN (H) - - 400
Latch circuit clearing power voltage 4 - 5 VIN(LA.OFF) 6.6 - 8.4 V
Overheat protection temp. - Tj(TSD) 140 - -
< Electrical features of control area:(Ta=25 ), Vin=18V >
16
Explanation for circuit operation
Specifications
ITEM Terminal Symbol Unit
MIN TYP MAX
Voltage via drain-source 1-2 VDSS 650 - - V
Drain leakage current 1 - 2IDSS - - 300
ON resistance 1-2 RDS(ON) - - 3.90 OHM
Heat resistance - ch-F - - 1.63 C/W
Switching time 1-2 Tf - - 250 SEC
4) Explanation for operation
When the VIN terminal (Pin No.4) voltage of STR-F6656, which is charged in C815 and C822
via starting resistance (R809+R817) and (R823+R824) at the early starting, reaches 10V, a
control circuit in SRT-F6656 starts.
Since the circuit current before 6656 operation is limited to 400 (MAX), a high starting
resistance can be used.
Because a sustaining current of latch circuit in 6656 is set to 500 (MAX), this starting
resistance needs to be set so that 500 or more current flows though AC input power is the
lowest.
Because the time until control circuit in 6656 starts is determined after AC input voltage is
input by (R809+R817), (R823+R824) and C815, C822 product, the power start gets slow if
C815 and C822 is set too high.
The voltage via a coil D (d1) of trans (T802. T803) is rectified and smoothed after operation
of 6656 and a stable voltage is supplied for Vin terminal. For coil D1, approx. 15.5V voltage is
rectified and smoothed via R813, R818, D810, D813, C815 and C822 and approx. 15V
voltage is supplied for Vin terminal of 6656.
Since VIN (OFF) voltage is set to 10V (TYP) in 6656, the terminal voltage supplied for Vin
terminal should not be less than 10V (15V at present). The voltage of coil d1 should be set
over operation stop voltage (VIN(OFF)=10V(MAX)) and under OVP operation voltage
(VOVP=16V(MIN)) at normal operating state.
5) Protection circuit
5-1) OCP circuit
This is an overcurrent protection circuit of pulse by pulse type that the peak of MOSFET
drain current is detected by 1 pulse and the output of oscillator is reversed.
To detect the MOSFET drain current, R810 and R820 are connected between source
terminal (Pin No.2) and GND terminal (Pin No.5) of MOSFET and the voltage drop is input to
OCP/FB terminal. The threshold voltage of OCP/FB is set to approx. 0.78V for GND.
5-2) Latch circuit
This circuit stops the operation of power circuit, keeping the oscillator output low when the
overvoltage protection circuit and overheat protection circuit are operated.
Because the circuit current gets less than 400uA when Vin terminal voltage is lower than
operation stop voltage (10V), it begins to increase. Because the circuit current increases
again when it reaches operation start voltage (16V), it decreases. Therefore, this circuit
prevents the Vin terminal voltage from rising, making it goes up and down between 10V and
17
Explanation for circuit operation
16V.
5-3) Overheat protection circuit
This circuit operates the latch circuit when the frame temps. of hybrid IC goes over 140
(MIN).
5-4) Overvoltage protection circuit
This circuit operates the latch circuit when Vin terminal voltage goes over 22.5V and protects
the Vin terminal of control circuit from overvoltage. The normal Vin terminal is supplied from
an auxiliary coil of trans and this voltage is proportioned to the output voltage. Thus, this
circuit works when the voltage detection circuit is open and the second overvoltage is output.
3. Deflection
3-1 Outline
This deflection PCB is composed of deflecting part to deflect 47", 55" CRT Projection TV and
7" CRT, high voltage generator part, dynamic focus part, ABL part and VM part.
3-2 Block diagram
18
Explanation for circuit operation
3-3 Organization of deflecting part
This smoothing part is designed to deflect a 55" CRT Projection TV and correct a screen. The
design specifications of this deflecting part are as follows.
1) Working frequency: Horizontal frequency (31.45KHz, 33.75KHz). Vertical frequency
(60Hz)
2) Vertical / Horizontal deflection
This deflection IC used in this deflecting part is TDA4856, the latest HC Control IC of
PHILPS. Co. Ltd. The main functions of this IC are shown below.
a. All functions concerned with vertical and horizontal deflection can be adjusted by HC
control of U-COM.
b. The geometrical correcting part such as V-S linearity, VC linearity, trapezoid, Side-pin W-
S, parallelogram and Side-pin balance are includes in the IC.
c. Twenty built-in D/A converter channels are adjustable respectively.
d. A vertical S-C correcting circuit is built in.
e. The amplitude and phase of a horizontal dynamic focus linked with horizontal size can be
adjusted.
f. A vertical dynamic focus circuit linked with vertical size is included.
g. A horizontal moire canceller circuit is built in.
h. A Sync On Green circuit is built in.
i. Vertical / Horizontal size can be controlled.
j. Vertical /Horizontal position can be controlled.
k. Vertical /Horizontal Sync of bipolarity can be input.
l. A vertical blanking generating and video clamp generating circuit are included. (Sand
castle output)
m. A vertical waveform of bipolarity is output.
n. A horizontal lock detecting circuit is included.
o. Low jitter
3-4 Explanation for operation
1) Vertical / Horizontal deflection IC circuit part
HD and VD signal supplied via connector PA402 in A/V board is input to H-in (Pin No.15)
and V-in (Pin No.14) of deflection IC as Sync. The input Sync goes through an internal Sync
processor and is output as H Drive to H-out (Pin No.8).
At this time, the internally processed Sync isn't affected by polarity and for H Sync, a
composite signal can be input. For H-OUT, the duty can be selected and controlled to 40,
50, 60% (+/- 3%) by I2C control. Free Run frequency at No Sync can be adjusted by I2C
control. Dividing a collector pulse from horizontal deflection, an internal PLL is taken after
FBP (Pin No.1) input and the phase is adjusted to horizontal Sync.
In this IC, all geometrical compensating waveforms related to horizontal are output from E/W
(Pin No.11), supplied for a horizontal B+ generator in a horizontal drive part, added to a
horizontal B+ waveform in the form of parabola and provided for D1 of horizontal output TR
(Q402). The horizontal dynamic focus signal from this IC is first amplified via an amplification
part (IF 11).
2) Horizontal drive part
This horizontal drive part consists of horizontal B+ supply part and horizontal output part.
19
Explanation for circuit operation
2-1) Horizontal B+ supply part
This horizontal B+ supply part cuts off horizontal B+ power by two TRs, using a Darlington
circuit. DC voltage supplied for E/W terminal (Pin No. 11) in deflection IC(I403) is input to EW
1st inversion circuit IF11 PIN2 by using EW waveform and then output to PIN1. The amplified
EW waveform is output to PIN7 and connected with B+ drive circuit, which is supplied for the
Darlington circuit composed of Q403 and Q404 through Q311 connector and C417, R429
horizontal. 135V via D415 and R433 is supplied for Q403, Q404 connector. When 100V is
supplied for Q403 base, DC voltage (100V-110V) amplified in Q404 and E/V compensating
waveform supply B+ for horizontal output Tr (Q402) by R409 and D405 via pin drive trans
T402 and dummy trans T403.
2-2) Horizontal output part
The horizontal output part makes a voltage and current enough for horizontal deflection
using a power supplied from horizontal B+ generator and drives H drive trans (T401) after
application to Q401. The drive pulse via H drive trans is supplied for the base of horizontal
output Tr (Q402) base and operates the horizontal output Tr. When it works. a horizontal
output voltage is made by using a horizontal deflection coil and retrace condenser (C407,
C408). At this time, the horizontal output voltage is approx. 1000V to 1200V and the retrace
time is approx. 4.0 sec. The horizontal output current via the deflection coil is supplied for CS
condenser (C409, C410).
3) Vertical drive part
The vertical drive part consists of +12V, -12V positive power, using TDA8172, vertical output
IC of SGS-THOMSON Co. Ltd. and performs vertical deflection and vertical-related
geometrical correction. The main operations of this vertical drive part are as follows. The
vertical waveform and vertical correction signal outputted to the vertical output terminal
(PIN12, PIN13) of vertical/horizontal deflection IC (I403) are input to inverted input terminal
(I412) of vertical output IC (I412), amplified in the vertical output I, outputted to the output
terminal (PIN6) and applied to vertical deflection coil. For the current via the deflection coil,
DC-feedback via R311 and AC feedback via C318 are executed.
4) High voltage generating part
The high voltage generating circuit uses a high voltage generator for projection, differently
from the conventional FBT method. This HVG has been developed by PHILIPS CO., LTD.
and performs the following operations. The HVG module is composed of 10 pins, 3 EHT
output holes and 1 focus output hole. Each terminal is displayed below.
PIN 1 : NC
PIN 2 : ABL ( BEAM CURRENT INFORMATION )
PIN 3 : GROUND (AUXILIARY VOLTAGE )
PIN 4 : AUXILIARY VOLTAGE ( -220V )
PIN 5 : NC
PIN 6 : NC
PIN 7 : OVP ( TEST POINT FOR OVER VOLTAGE PROTECTION )
PIN 8 : ON/OFF (ON/OFF 5V)
PIN 9 : GROUND
PIN10 : VB+ ( POWER SUPPLY VOLTAGE )
20
Explanation for circuit operation
When B+ 135V is supplied and +5V is applied, approx. 31KV high voltage and 11.6KV focus
voltage are generated automatically. If EHT of HVG is outputted more than 35KV, HVG
module starts over voltage protection to stop the high voltage.
5) Spot killer components
Approx. -220V voltage made by using HVG high voltage output voltage is supplied from HVG
PIN4, rectified and smoothed to D819 and C425 and used as spot killer power. After this
power is divided into R448 and R449 normally, a voltage near to -20V via R465 is supplied
for CRT board GRID 1 via connector PA13 G1. But, at first AC power ON, the spot killer
signal supplied via a connector PA15M in main board is provided for the base of Q412. At
AC power OFF, a voltage near to -220V via Q414 is provided for GRID 1 of CRT board via
G1 of connector PA16M. As a result, the screen gets dark to prohibit the generation of a
spot.
6) Dynamic focus voltage generator
The dynamic focus voltage provides a parabola waveform conforming to CRT spec.
(horizontal:1000V, vertical:200V) for CRT to make the focus of 7" CRT optimum. A D/F
waveform from 1403 pin32 is amplified approx. 100 times in an amplifying circuit composed
of OP AMP and a parabola waveform is amplified approx. 1000Vp-p in an amplifying circuit
composed of QF11, 12, 13. Then, they are input to QF14 base. The horizontal waveform of
1300Vp-p left in T402 terminal No.16 is rectified and smoothed to DF13, 12, RF17, CF11, 12
and supplied for QF14 collector as B+ for dynamic focus.
7) ABL input part
The ABL current supplied from main board via the ABCL terminal of a connector PA401
flows in via FBT PIN2. Then, the current amount is detected, the BCL circuit is operated in
the main board and the maximum current amount is controlled. If a beam current begins to
flow about 1.5mA, the ABL circuit will work and if about 1.8mA, the ABL feedback circuit will
work. Therefore, be careful not to be more than 1.8mA.
8) VM (Velocity Modulation) outline correction part
The outline correction circuit is operated in exclusive correction IC, IV11 (STK396-130). The
VM waveform made in the main PCB is input to the deflection PCB PA401 PIN1. The input
1Vp-p signal is input to IV11 PIN1. The input signal is amplified about 100 to 120Vp and
output to IV11 PIN9. Then, it is input to IV11 PIN10 via the circuit composed of VM coil PV11,
12, 13. The power of +12V and +135V GND are used.
21
Explanation for circuit operation
Explanation for circuit operation
22
Explanation for circuit operation
23
Explanation for circuit operation
24
Explanation for circuit operation
25
Explanation for circuit operation
26
Explanation for circuit operation
27
Explanation for circuit operation
4. Video signal process
4-1. Block Diagram
4-2. Video processor
This part switches and processes DTV input, DVD input, external video signal and TV
signal.
1) Signal input/output
The signal input is composed of 2 pairs of NTSC TV signals (2 tuners), 3 pairs of NTSC
external inputs (Video, S-VHS 3 pairs respectively), 2 pairs of component inputs and 1 pair
of monitor outputs.
2) Video input switching
2 pairs of NTSC TV signals and 3 pairs of NTSC external input from the main tuner
(TU701) and sub tuner (TU702) is switching in a IA01 AV switch and 2 pairs of component
input is switching in a IA05 video selector.
CXA1855Q outputs 4 pairs as switching IC with 5 pairs input and CXA2151Q outputs a
YCbCr signal by 4 pairs input. The output signal is amplified 6dB.
CVBS (Main) and Y, C signal from QXA1855Q are input to 3D Comb-filter (ICB1), 4801
format between CVBS (Sub) and IA05 output is input to ICD1 and 480P and 10801 signal
of IA05 are input to IC201.
ICB1 performs Y, C division and YCNR (YC Noise Reduction) function, equipped with
internal AD converter and 4M bit frame delay memory as a three-dimensional Y, C divided
IC.
Y/C signal from ICB1, caption data decoded in caption IC (IC206) and 4801 signal of IA05
are input to the main video processor IC, VSP9407B (ICD1).
28
Explanation for circuit operation
When PIP function is executed in `different application mode' signal processing VSP9407B,
the video signal corresponding to a sub screen (Sub CVBS from TU702) is input.
VSP9407B performs a scan rate conversion of main video signal and sub video signal from
480I to 480P, overlaps the main video and sub video to convert to PIP screen and outputs
them to IC201 (CXA2101Q) in YcbCr-H-V format. And, a multi component processor,
IC210 performs a final switching for YcbCr-H-V signal of VSP9407B and YUV (480P,
10801) signal from IA05.
3) Video signal processing
CXA2101 IC can switch OSD by 4 pairs of YUV input and RGB OSD input and react two
kinds of color difference signals of NTSC (YUV) and HD (YpbPr) by YUV to RCB matrix
switch function. It can also control ABL/ACL gain and start level by contrast, brightness,
sharpness, color, tint (Hue) control function and ABL/ACL input terminal. And, it performs
black/white gradation correction and has a voltage input terminal for DC play ratio control.
CXA2101 performs LTI (Luminance Signal Edge Enhancement Setting) and CTI (Color
Difference Signal Edge Enhancement Setting), and generates a signal for VM.
CXA2101 (IC201) performs a final signal processing after switching YCbCr (480P) signal
from VSP9407B and YUV (480P, 1080I) from CXA2151 and outputs the RGB signal
controlled by user control to CRT drive part after mixing it with OSD signal.
5. Sound
5-1 Switching part
For NTSC TV input, SIF signal from main tuner is input to IC602 (MSP3421) PIN67, and 3
pairs of external inputs, audio signals are switched in IA01, output to #32 (R), #33(L) and
input to IC601 #47 (Main L), #48 (Main R).
For audio signals of component 1,2 (DTV, DVD compatible) input, component 1 is input to
#50 (L), #51 (R) and component 2 is input to #53(L), #54(R).
29
Explanation for circuit operation
5-2. Sound Processing
As shown above, the MSP4321 outputs the main L/R to PIN27, 28 after switching NTSC
S/F external input L/R and component 1,2 (DTV, DVD compatible) L/R signals. The main
functions of the MSP3421 are volume control, equalizing and balancing. The SIF signal
that is input to #67 goes through AGC, A/D, demodulation and demphosis block. The audio
signal detected by FM is demodulated and output.
For sound output, the main L/R that is output from IC601 PIN27, 28 is input to 1601
(FDA7265) AMP PIN7, 11 and the sound is amplified from FDA7265 and connected with
L/R speaker.
6. Convergence part
6-1. Outline
This convergence supplies a constant waveform for R, G, B SUB-DY to evenly show R, G, B
screen of 55" CRT Projection TV.
30
Explanation for circuit operation
6-2. Block Diagram
6-3. Composition
1) CM0021AF
As a digital convergence IC, this inputs HBLK and VBLK, adjusts a register in IC, makes
and supplies a digital convergence waveform of RH, GH, BH, RV, GV and BV. It also has
Save U-Com function and controls EEPROM (I503: 24WC32) which stores the
convergence control data by the order of Master U-Com.
The main features of this IC are as follows.
1-1) Feature
Multiscan : NTSC/PAL/HDTV, Progressive/Interlace
6ch/16bits Digital Outputs for Convergence Correction
2ch Analog Outputs for Dynamic Focus
Test Pattern Generator for Convergence
2-Port IIC Interface for EEPROM and U-COM
1-2) Data Capacity
504 words : Fine Adjustment
33 words : Coarse Adjustment
9 words : Dynamic Focus
582 Words in Total
31
Explanation for circuit operation
2) CD0031AM
This converts the digital convergence waveform to analog waveform as a 6-channel, 16 bit D/A
converter IC for digital convergence.
The features of this IC are as follows.
High Sampling Rate Operation : 1MHz
Differential Non-Linearity Error : +/- 1 LSB
=> Operate on 1H to Over 3H Application
Center Voltage Output
=> Same Electrical Characteristics of Center Voltage Output and RH, GH, BH, RV, GV, BV's
Zero Cord Outputs
Mute Function
3) Others
3-1) KF353
This is used as a level shift and low pass filter (1506-1511) of RH, GH, BH, RV, GV and BV.
3-2) STK392-020 (1940, 1905)
This uses a 3 channel AMP to apply RH, GH, BH, RV, GV and BV via level shift and low
pass filter (1506-1511)to a Sub-DY coil.
32
Explanation for circuit operation
7. CRT AMP
The video signal that is first amplified in PGB processor is input to video AMP in approx. 3.5Vp-
p level. TDA111Q used as a video AMP is a 13Mhz band AMP which outputs a video near to
Vdd according to gain control voltage when Vdd is 200V. The following figure shows the internal
block diagram of TDA6111Q.
Block diagram of TDA6111Q
There are two cathode outputs and a independent feedback output. Low input (Vdd) is 12V and
high input (Vddh) is 200V. A peaking circuit is designed in Amp IC input and output part for high
band compensation. The entire output gain is about 34db.
33
6. TROUBLE SHOOTING
When the screen
doesn't turn up
AV/RF Signal
YES NO Check
Is there OSD the tuner
on the screen? OSD (TU701 & TU702
NO
No screen mode 1 No screen mode 1 Check LA1 TV video signal
1. TV external input 1. TV (RF signal) Main tuner (TV701 CVBS #41)
2. Component input 2. AV input Sub tuner (TV702 CVBS #27)
2
2
Check LA5 input/output
Input Check LA1 video signal
- COMP1:Y-#43, Cb/Pb-#42, Cr/Pr-#41 Video1:#43-CVBS, #45-Y, #47-C
- COMP2:Y-#3, Cb/Pb-#2, Cr/Pr-#1 Video2:#1-CVBS, #3-Y, #5-C
Output Video3:#7-CVBS, #9-Y, #11-C
- Y-#27, Cb/Pb-#26, Cr/Pr-#25
NO
Check LA1 output signal
Check input signal 1. CVBS_Main:#34, Y:#37, C:#39
1 2. CVBS_Sub:#17
1. 480i Check external
2. 480p/1080I input signal
2 1
Check ICB1 input/output
Y/CVBS_Main Input:#88
OSD C Input:#96
Y/CVBS_Main Output:#84
Check IC201 input/output C Output:#83
Input
-ICD1 Output
Check I701 OSD signal Y:#69, Cb:#68, Cr:#67, H:#66, B:#65
R, G, B:#64, #63, #62 -IA5 Output
BL:#61 Y:#5, Cb:#4, Cr:#3
Check ICD1 input/output
-OSD
Input
R, G, B:#50, #51, #52
1. Y/CVBS_Main:#55, C_Main:#54
BL:#49
2. CVBS_Sub:#52
Output
3. 480i:#46(Cr), #47(Y), #48(Cb)
R, G, B:#35, #37, #39
Output
HS:#29, VS:#28
Y:#2, Cb:#79, Cr:#76, H:#17, V:#23
END
34
TROUBLE SHOOTING
When no sound
is heard
Check IC601 sound signals.
#27, #28 YES
NO
Check IC601 input sound signals.
SIF:#67 A/V:#47, #48
Component1:#50, #51
Componen2:#53, #54
YES
NO
IC601 NO Chack YES
#38, #39, #40 C604, RC605
C605, RC615 IC601#47, #48
Check B+ DC603, C606 IA01#32, #33
Check C612
NO
YES NO NO YES
IC606 NO
LC601, C601, CC601 Check
#11, #12, #13 RC601, L601, C618 Check Check Check
IA01 RC606
#65, #66, #80 CC615, LC602, C602 IA01 IA01
Check CC607 #44,#46 RC607
Check B+ #2,#4 #8,#10
sound. C608
sound. sound.
C609
YES
NO NO
NO
Check Check
IC601 #2, #3 DC601, DC602 Check
I2C RC602, RC603 Check Check
CC107CCI09
CC120,CC122 CC102CCI04C
RCT13, RCT14
YES CCK2,CCK3 CK5CCK6
DCT11
RCK4, RCK5 RCK9, RCK10
NO DCT12, DCT14
Check DCK5, DCK6 DCK13, DCK14
IC601 #21 Check DCT15, DCT16
DCK7, DCK8 DCK15, DCK16
Reset C603, RC604 DCT17
YES #3
#1
END
#2
35
TROUBLE SHOOTING
#2
#1
#3
YES NO NO NO
NO
Check Check When component
X601,CC605 When IC601 When component
IC601#71, #72 IC601#53 #54
X-TAL CC606 #67 SIF doesn't IC601#50 #51
work, check sounds aren't sounds aren't
TU701 tuner. heard, heard,
YES
Check OC614, C617,
C607, OC613 and
replace IC601.
Check
RC608, RC609, C610 Check
C611, CCK10, CCK11 RC610, RC611, C612
RCK17, RCK18 C613, CCK12, CCK13
END DCK22, DCK23 RCK22, RCK23
DCK24, DCK25 DCK26, DCK27
DCK28, DCK29
END
Check I650 YES
L/R Input:#7, #11, L/R Output:#2, #4, #8, #10
A MUTE:#5
END
36
TROUBLE SHOOTING
No raster.
Check IIC bus communication between main assy
and I403
Vertical deflection NO Check main
5Vp-p
assy, 1403
Check I403 #8 (H-drive output)
0.7Vp-p
31.5KHz
Horizontal
deflection
Check D drive signal in Q401 collector Check H drive signal input in Q402 base
2Vp-p
45Vp-p
6Vp-p NO
31.5KHz
Check Q416
31.5KHz
31.5KHz
Check H driver B+ voltage in T402 #7
NO
60KHz
Check Q404 collector 135V
2Vp-p Check
NO
R409
290-110V
Check R443
37
TROUBLE SHOOTING
Check R443
NO
Check PB801 135V When power isn't supplied
Output E/W signal in I401 #7 Horizontal drive B+ is input to Q403 base
60Hz
0.5VP-p
0.5VP-p
5V
90V
60Hz
Voltage waveform of Q402 collector is
shown below.
If resistance between Q425 collector and GND
is near 0