Zenith DVP7771 Schematic

1-1

CONTENTS

SECTION 1 . . . . SUMMARY

SECTION 2 . . . . EXPLODED VIEWS

SECTION 3 . . . ELECTRICAL

SECTION 4 . . . REPLACEMENT PARTS LIST

1-2

SECTION 1

SUMMARY

CONTENTS

PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS .................................. 1-3

SAFETY CHECK AFTER SERVICING ............................................................................................ 1-4

SPECIFICATIONS ............................................................................................................................ 1-5

1-3

CAUTION : DO NOT ATTEMPT TO MODIFY THIS PRODUCT IN ANY WAY,
NEVER PERFORM CUSTOMIZED INSTALLATIONS WITHOUT MANUFAC­TURER’S APPROVAL. UNAUTHORIZED MODIFICATIONS WILL NOT ONLY
VOID THE WARRANTY, BUT MAY LEAD TO YOUR BEING LIABLE FOR ANY
RESULTING PROPERTY DAMAGE OR USER INJURY.

SERVICE WORK SHOULD BE PERFORMED ONLY AFTER YOU ARE
THOROUGHLY FAMILIAR WITH ALL OF THE FOLLOWING SAFETY
CHECKS AND SERVICING GUIDELINES. TO DO OTHERWISE,
INCREASES THE RISK OF POTENTIAL HAZARDS AND INJURY TO THE
USER.

WHILE SERVICING, USE AN ISOLATION TRANSFORMER FOR PROTEC­TION FROM A.C. LINE SHOCK.

SAFETY CHECKS

AFTER THE ORIGINAL SERVICE PROBLEM HAS BEEN CORRCTED. A
CHECK SHOULD BE MADE OF THE FOLLOWING.

SUBJECT : FIRE & SHOCK HAZARD

1. BE SURE THAT ALL COMPONENTS ARE POSITIONED IN SUCH A WAY
AS TO AVOID POSSIBILITY OF ADJACENT COMPONENT SHORTS.
THIS IS ESPECIALLY IMPORTANT ON THOSE MODULES WHICH ARE
TRANSPORTED TO AND FROM THE REPAIR SHOP.

2. NEVER RELEASE A REPAIR UNLESS ALL PROTECTIVE DEVICES
SUCH AS INSULATORS, BARRIERS, COVERS, SHIELDS, STRAIN
RELIEFS, POWER SUPPLY CORDS, AND OTHER HARDWARE HAVE
BEEN REINSTALLED PER ORIGINAL DESIGN. BE SURE THAT THE
SAFETY PURPOSE OF THE POLARIZED LINE PLUG HAS NOT BEEN
DEFEATED.

3. SOLDERING MUST BE INSPECTED TO DISCOVER POSSIBLE COLD
SOLDER JOINTS, SOLDER SPLASHES OR SHARP SOLDER POINTS.
BE CERTAIN TO REMOVE ALL LOOSE FOREIGN PARTICLES.

4. CHECK FOR PHYSICAL EVIDENCE OF DAMAGE OR DETERIORATION
TO PARTS AND COMPONENTS. FOR FRAYED LEADS, DAMAGED
INSULATION (INCLUDING A.C. CORD). AND REPLACE IF NECESSARY
FOLLOW ORIGINAL LAYOUT, LEAD LENGTH AND DRESS.

5. NO LEAD OR COMPONENT SHOULD TOUCH A RECIVING TUBE OR
A RESISTOR RATED AT 1 WATT OR MORE. LEAD TENSION AROUND
PROTRUNING METAL SURFACES MUST BE AVOIDED.

6. ALL CRITICAL COMPONENTS SUCH AS FUSES, FLAMEPROOF
RESISTORS, CAPACITORS, ETC. MUST BE REPLACED WITH EXACT
FACTORY TYPES, DO NOT USE REPLACEMENT COMPONENTS
OTHER THAN THOSE SPECIFIED OR MAKE UNRECOMMENDED CIR­CUIT MODIFICATIONS.

7. AFTER RE-ASSEMBLY OF THE SET ALWAYS PERFORM AN A.C.
LEAKAGE TEST ON ALL EXPOSED METALLIC PARTS OF THE CABI­NET, (THE CHANNEL SELECTOR KNOB, ANTENNA TERMINALS. HAN­DLE AND SCREWS) TO BE SURE THE SET IS SAFE TO OPERATE
WITHOUT DANGER OF ELECTRICAL SHOCK. DO NOT USE A LINE
ISOLATION TRANSFORMER DURING THIS TEST USE AN A.C. VOLT­METER, HAVING 5000 OHMS PER VOLT OR MORE SENSITIVITY, IN
THE FOLLOWING MANNER; CONNECT A 1500 OHM 10 WATT RESIS­TOR, PARALLELED BY A .15 MFD. 150.V A.C TYPE CAPACITOR
BETWEEN A KNOWN GOOD EARTH GROUND (WATER PIPE, CON­DUIT, ETC.) AND THE EXPOSED METALLIC PARTS, ONE AT A TIME.
MEASURE THE A.C. VOLTAGE ACROSS THE COMBINATION OF 1500
OHM RESISTOR AND .15 MFD CAPACITOR. REVERSE THE A.C. PLUG
AND REPEAT A.C. VOLTAGE MEASUREMENTS FOR EACH EXPOSED
METALLIC PART. VOLTAGE MEASURED MUST NOT EXCEED 75
VOLTS R.M.S. THIS CORRESPONDS TO 0.5 MILLIAMP A.C ANY
VALUE EXCEEDING THIS LIMIT CONSTITUTES A POTENTIAL SHOCK
HAZARD AND MUST BE CORRECTED IMMEDIATELY.

SUBJECT: GRAPHIC SYMBOLS

THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN
AN EQUILATERAL TRIANGLE, IS INTENDED TO ALERT THE
SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED
“DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAG-
NITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK.

THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIAN­GLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO
THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN
SERVICE LITERATURE.

SUBJECT : X-RADIATION

1. BE SURE PROCEDURES AND INSTRUCTIONS TO ALL SERVICE PER­SONNEL COVER THE SUBJECT OF X-RADIATION. THE ONLY POTEN­TIAL SOURCE OF X-RAYS IN CURRENT T.V. RECEIVERS IS THE PIC­TURE TUBE. HOWEVER, THIS TUBE DOES NOT EMIT X-RAYS WHEN
THE HIGH VOLTAGE IS AT THE FACTORY SPECIFIED LEVEL. THE
PROPER VALUE IS GIVEN IN THE APPLICABLE SCHEMATIC. OPERA­TION AT HIGHER VOLTAGES MAY CAUSE A FAILURE OF THE PIC­TURE TUBE OR HIGH VOLTAGE SUPPLY AND, UNDER CERTAIN CIR­CUMSTANCES, MAY PRODUCE RADIATION IN EXCESS OF DESIR­ABLE LEVELS.

2. ONLY FACTORY SPECIFIED C.R.T. ANODE CONNECTORS MUST BE
USED. DEGAUSSING SHIELDS ALSO SERVE AS X-RAY SHIELD IN
COLOR SETS, ALWAYS RE-INSTALL THEM.

3. IT IS ESSNTIAL THAT SERVICE PERSONNEL HAVE AVAILABLE AN
ACCURATE AND RELIABLE HIGH VOLTAGE METER. THE CALIBRA
TION OF THE METER SHOULD BE CHECKED PERIODICALLY
AGAINST A REFERENCE STANDARD, SUCH AS THE ONE AVAILABLE
AT YOUR DISTRIBUTOR.

4. WHEN THE HIGH VOLTAGE CIRCUITRY IS OPERATING PROPERLY
THERE IS NO POSSIBILITY OF AN X-RADIATION PROBLEM. EVERY
TIME A COLOR CHASSIS IS SERVICED. THE BRIGHTNESS SHOULD
BE RUN UP AND DOWN WHILE MONITORING THE HIGH VOLTAGE
WITH A METER TO BE CERTAIN THAT THE HIGH VOLTAGE DOES
NOT EXCEED THE SPECIFIED VALUE AND THAT IT IS REGULATING
CORRECTLY, WE SUGGEST THAT YOU AND YOUR SERVICE ORGA­NIZATION REVIEW TEST PROCEDURES SO THAT VOLTAGE REGU­LATION IS ALWAYS CHECKED AS A STANDARD SERVICING PROCE­DURE. AND THAT THE HIGH VOLTAGE READING BE RECORDER ON
EACH CUSTOMER’S INVOICE.

5. WHEN TROUBLESHOOTING AND MAKING TEST MEASUREMENTS IN
A PRODUCT WITH A PROBLEM OF EXCESSIVE HIGH VOLTAGE,
AVOID BEING UNNECESSARILY CLOSE TO THE PICTURE TUBE AND
THE HIGH VOLTAGE SUPPLY. DO NOT OPERATE THE PRODUCT
LONGER THAN IS NECESSARY TO LOCATE THE CAUSE OF EXCES
SIVE VOLTAGE.

6. REFER TO HV. B+ AND SHUTDOWN ADJUSTMENT PROCEDURES
DESCRIBED IN THE APPROPRIATE SCHEMATIC AND DIAGRAMS
(WHERE USED).

SUBJECT: IMPLOSION

1. ALL DIRECT VIEWED PICTURE TUBES ARE EQUIPPED WITH AN INTE
GRAL IMPLOSION PROTECTION SYSTEM, BUT CARE SHOULD BE
TAKEN TO AVOID DAMAGE DURING INSTALLATION, AVOID
SCRATCHING THE TUBE. IF SCRATCHED REPLACE IT.

2. USE ONLY RECOMMENDED FACTORY REPLACEMENT TUBES.

SUBJECT : TIPS ON PROPER INSTALLATION

1. NEVER INSTALL ANY PRODUCT IN A CLOSED-IN RECESS, CUBBY­HOLE OR CLOSELY FITTING SHELF SPACE. OVER OR CLOSE TO
HEAT DUCT, OR IN THE PATH OF HEATED AIR FLOW.

2. AVOID CONDITIONS OF HIGH HUMIDITY SUCH AS: OUTDOOR PATIO
INSTALLATIONS WHERE DEW IS A FACTOR, NEAR STEAM RADIA­TORS WHERE STEAM LEAKAGE IS A FACTOR, ETC.

3. AVOID PALCEMENT WHERE DRAPERIES MAY OBSTRUCT REAR
VENTING. THE CUSTOMER SHOULD ALSO AVOID THE USE OF DEC­ORATIVE SCARVES OR OTHER COVERINGS WHICH MIGHT
OBSTRUCT VENTILATION.

4. WALL AND SHELF MOUNTED INSTALLATIONS USING A COMMER­CIAL MOUNTING KIT. MUST FOLLOW THE FACTORY APPROVED
MOUNTING INSTRUCTIONS A PRODUCT MOUNTED TO A SHELF OR
PLATFORM MUST RETAIN ITS ORIGINAL FEET (OR THE EQUIVALENT
THICKNESS IN SPACERS) TO PROVIDE ADEQUATE AIR FLOW
ACROSS THE BOTTOM, BOLTS OR SCREWS USED FOR FASTENERS
MUST NOT TOUCH ANY PARTS OR WIRING. PERFORM LEAKAGE
TEST ON CUSTOMIZED INSTALLATIONS.

5. CAUTION CUSTOMERS AGAINST THE MOUNTING OF A PRODUCT ON
SLOPING SHELF OR A TILTED POSITION, UNLESS THE PRODUCT IS
PROPERLY SECURED.

6. A PRODUCT ON A ROLL-ABOUT CART SHOULD BE STABLE ON ITS
MOUNTING TO THE CART. CAUTION THE CUSTOMER ON THE HAZ­ARDS OF TRYING TO ROLL A CART WITH SMALL CASTERS ACROSS
THRESHOLDS OR DEEP PILE CARPETS.

7. CAUTION CUSTOMERS AGAINST THE USE OF A CART OR STAND
WHICH HAS NOT BEEN LISTED BY UNDERWRITERS LABORATORIES,
INC. FOR USE WITH THEIR SPECIFIC MODEL OF TELEVISION
RECEIVER OR GENERICALLY APPROVED FOR USE WITH T.V.’S OF
THE SAME OR LARGER SCREEN SIZE.

8. CAUTION CUSTOMERS AGAINST THE USE OF EXTENSION CORDS,
EXPLAIN THAT A FOREST OF EXTENSIONS SPROUTING FROM A SIN­GLE OUTLET CAN LEAD TO DISASTROUS CONSEQUENCES TO
HOME AND FAMILY.

PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS

A.C. VOLTMETER

GOOD EARTH GROUND
SUCH AS THE WATER
PIPE. CONDUIT. ETC

PLACE THIS PROBE
ON EACH EXPOSED
METAL PART

1-4

Fig. 3

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 original positions. Afterwards, perform the following tests and confirm the specified
values in order to verify compliance with safety standards.

• Insulation resistance test

confirm the specified insulation resistance or greater between power cord plug prongs and externally exposed
parts of the set (RF terminals, antenna terminals, video and audio input and output terminals, incrophone jacks,
earphone jacks, etc.) See table below.

• Dielectric strength test

Confirm specified dielectric strength or greater between power cord prongs and exposed accessible parts of
the set (RF terminals, antenna terminals, video and
audio input and output terminals, incrophone jacks,
earphone jacks, etc.) See table below.

• Clearance distance

When replacing primary circuit components, confirm
specified clearance distance (d), (d') between sol­dered terminals, and between terminals and sur­rounding metallic parts. See table below.

Table 1 : Ratings for selected areas

* Class II model only.

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

country and locality.

• Leakage Current test

Confirm 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.)

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 both terminals of
load Z. See figure and following table.

Table 2:Leakage current ratings for selected areas.

Note. This table is for IEC member only. Be sure to confirm the precise values for your particular country and

Note. locality.

Fig. 2

AC Line Voltage

AC Line Voltage

100 to 130 V

200 to 240 V

*100 to 130 V

*200 to 240 V

Europe

Australia

Europe

Australia

Other terminals

Antenna earth

terminals

i

E 0.7m A peak

i E 2m A DC
i E 0.7m A peak

i E 2m A DC

F 10 MΩ/500 V DC

4kV 1 minute

F 6mm(d)
F 8mm(d)

(a Power cord)

Region

Load Z Leakage Current(i)

Earth Ground

(B) to :

Region

Insulation

Resistance

Dielectric

Strength

Clearance

Distance(d),(d)

2k

Ω

50k

Ω

d

Primary circuit terminals

Chassis

a

Exposed
accessible
part

Load

Z

Earth Ground,
Power cord plug prongs

B

AC Voltmeter

1-5

SPECIFICATIONS

General

ITEM SPECIFICATIONS

DISC FORMAT DVD Disc: DVD VIDEO Specification Book.

CD-DA Disc: RED Book.

CD-R/RW Disc

VIDEO SYSTEM PAL, NTSC

DATA MULTIPLEXING MPEG-2(ISO/IEC 13818-1)

VIDEO DECODING Standards MPEG-1, MPEG-2

AUDIO COMPRESSION Dolby Digital: ATSC Standard for ATV

MPEG-1, MPEG-2

AUDIO DIGITAL I/F S/P DIF(IEC-1937/958)

REGULATIONS Safety:CSA UL

Laser: FDA CFR21

EMC: CSA FCC

Regional code Refer to DVD VIDEO Specification Book.

RATING

ITEM SPECIFICATIONS

POWER REQUIREMENT DC Adaptor 9.8V, Battery 8.0V

POWER CONSUMPTION 10W With Battery

OPERATING TEMPERATURE RANGE 0°C ~ 40°C

STORAGE TEMPERATURE RAGE -20°C ~ 60°C

STANDARD CONDITION 25°C, 65%RH

ACCESSORIES

ITEM SPECIFICATIONS NOTE

RCA A/V CABLE Cable Length 1.5m

S-CABLE Cable Length 1.5m optional

ADAPTOR UNIT DC 9.8V Cable Total Length 1.1m

(Include Adaptor)

POWER CABLE Cable Lenth 1.4m

BATTERY PACK Li-ion, Rechargable, 5600mAh

REMOTE CONTROL UNIT

BATTERY FOR REMOTE Lithium * 1EA

OWNERS MANUAL

2-1

SECTION 2

EXPLODED VIEWS

CONTENTS

EXPLODED VIEWS .....................................................................................................................2-2

Cabinet and Main Frame Section ..............................................................................................2-2

Deck Mechanism Section ...........................................................................................................2-3

Packing Accessory Section .......................................................................................................2-4

2-2

EXPLODED VIEWS

• Cabinet and Main Frame Section

270

A46

451

271

451

290

268

260

261

262

264

269

267

266

263

251

250

278

451

279

254

255

252

253

257

258

256

272

A49

276

273

274

275

452

286

452

280

A47

282

265

284

283

287

281

285

A48

451

A43A

A44B

A44A

A43

A43B

A49A

A00

A41

A

5

4

3

2

1

BCD

2-3

• Deck Mechanism Section

430

430

001

430

002

002

006

005

004

003

002

431

431

007

2-4

• Packing Accessory Section

PACKING SHEET

804

PACKING

OPTIONAL PARTS

803

OWNER'S MANUAL

801

REMOCON

900

R/C BATTERY

808

BOX CARTONX

802

PACKING

803

812

830

PLUG ASS'Y 2WAY

ADAPTER

814

PLUG ASS'Y

813

S-VHS CABLE

BATTERY

TUNER

809

820

3-1

SECTION 3

ELECTRICAL

CONTENTS

LCD PART ................................................................................................................3-2

ELECTRICAL TROUBLE SHOOTING GUIDE ......................................................3-17

BLCOK DIAGRAMS ..............................................................................................3-26

CIRCUIT DIAGRAM ................................................................................................3-32

PRINTED CIRCUIT DIAGRAMS ............................................................................3-62

3-2

How to adjust LCD COLOR

1) Connect CON 803, power apply, and then check DC power(DC 9.8V).
(CE8G1: -15V, CE8F9: +17V, CE8F8: +7.5V, CE8F6: +5V, CE8F7: +3.3V)

2) VCO adjusting; Sync. adjusting

* VR801 adjust 6.5Vp-p while viewing TP(VCOM)’s waveform, and VR815 adjust with 63.5us(center in display).

3) RGB-AMP adjusting; Black Level adjusting --- Fixed

Input RAMP (or 5STEP) signal, TP(G) waveform adjust while viewing.
(Adjust between 0.5V ~ 4.5V)

4) BRIGHT adjusting; adjusts Brightness(Black Level variable)(VR808: 2V±0.1)

* Input RAMP signal, adjust black LEVEL while viewing TP(G) waveform.

6.5Vp-p

GND

4V

2.5V

4.5V

0.5V

GND

White

Black

4.5V

0.5V

GND

White

White

Black

Black

63.5uS

LCD PART

3-3

* To set final settings, fit best display guality while viewing screen.

• or, after inputting 5STEP signal, adjust as CONT adjusting as shown below.(COLER MAX)

• adjust best results while viewing oscilloscope and Screen.

5) GAM0, GAM1 (GAM0: Black side, GAM1: White side) - Fixed(VR810, 811)

* Input RAMP signal and view TP(G) waveform, deside that GAM0 is black side knee point and GAM1 iswhite-

side knee point.

• GAM0 and GAM1 adjusting performs with CONT(VR803), because the amplitude linked.

6) CONT(VR803); White LEVEL Variable (2.8±0.1V)

Input RAMP signal, View TP(G) wareform, adjust amplitude to 3.2 ~ 3.5.

(VR803) (2.9V)

3.4

3.2

3.1

2.7

1.5

1

2.1

0.6

GND

BRIGHT

Black

(VR808)(2V)

3-4

7) TINT(VR805); Color Adjusting(3V±0.1)

* Input COLOR BAR signal, view TP(B) waveform.

• adjusts White, Cyun, Magenta, Blue Signal conformity.

8) BLK1(VR814), BLK2(VR813); SIDE BLOCK Adjusting - Fixed.

• Input RAMP signal and SIDE1 S/W ON, view the TP(G) waveform.

• RGB-AMP adjusts same as LIMIT LEVEL.

Following items, adjust best display while viewing screen.

9) VCOM(VR817); Flicker adjusting

• Input 1 Line opposite signal, adjust Black maximum.

• or, Input 10 STEP signal, adjust Black maximum.

• Adjust best signal in ZOOM condition.

10) WB-B(VR807)(2.1V), WB-R(VR806)(2.3V); Brighness adjusting

• Input 5STEP, 10STEP and Black and White signal, adjusts Brightness Balance while viewing screen.
* adjust WB-B: whole screen changes Blue

) yellow.

* adjust WB-R: whole screen changes Red

) green.

• or, adjust color Brightness

11) COLOR(VR804); Color density adjusting - External Volume

• Adjust best condition with inputting screen, it is relation with S/N

12) Shapeless(VR802); Fixed

• Adjust not so much because in relation with S/N.

GND

3.5V

0.6V

Magenta BlueCyanWhite

GND

BLK1

BLK2

3-5

DESPLAY CONDITION? INVERTOR ABNORMAL

appear shadow form interference
in black background

There is only bright light.(LCD B/D abnormal)

FUSE Replace

IC8F1, IC8F2 Check and Replace

T801, D8F1, D8F2, D8F3 Check

IC8F3, IC8F4 Check and Replace

A/V IN S/W Check

X801, C832 Replace

IC801, IC803, Q806 Check and Replace

IC808, Q811, Q812, QQ813 Check and Replace

D801, L809, IC806 VCO Check and Replace

Q810, IC807 Check and Replace

FUSE(F801)Normal?

Q8F1 Normal operate?

7.5V, 17V, -15V Normal?

+5V, +3.3V Normal?

Y/C Display signal?

X801 operate?

R.G.B signal output?

VCOM signal?(6.5Vpp)

VCO Normal operate?

H/V SYNC?

YES

YES

NO

NO

NO

NO

NO

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

YES

YES

LCD TROUBLE SHOOTING GUIDE(1/2)

3-6

IC805’s CLK and CONT signal?

IC805 Replace

MAIN B/D Check

LCD MODE CONT signal?

ALL “LOW”(NORMAL condition)

TFT LCD pressure voltage?

+17V, -15V, +5V, +3.3V

Power source and D803, D804 Check

TFT LCD Normal?

Replace

Color Adjusting Normal?

Readjust as adjustement standard.

Each CONNECTOR?

Replace and Reassemble

INVERTOR Normal?

Replace

END

YES

YES

YES

YES

YES

YES

YES

NO

NO

NO

NO

NO

NO

NO

LCD TROUBLE SHOOTING GUIDE(2/2)

3-7

LCD BLOCK DIAGRAM

CON

8

0

3

INVERTER

TFT LCD

CROMA

IC

IR3Y29BM

CONTROL

IC

MN5814

POWER

LCD MODE CONTROL

Y/C,COMPOSITE

DC9V

AC550V

SYNC

SEP

VCO

H,V

R.G.B

CONTROL

+3.3V

+5V

7.5V

-17V

-15V

3-17

ELECTRICAL TROUBLE SHOOTING GUIDE

1. Power (DC-DC Converter) Circuit

A.

NO POWER ON
by ADAPTOR

NO POWER ON
by BATTERY

Is ADAPTOR
OUT 9.8V?

Is BATTERY

OK?

Is F901 OK?

Is F101 OK?

Is LF101 OK?

Replace F101

YES

Is D101 OK?

Replace D101

Replace ADAPTOR

NO +1.8V

Is Q109 OK?

NO +12VNO + 5V

NO +3.3V

NO LCD POWER

Replace

Q109

Is E+5V OK?

Is Q112 OK ?

Is Q113 OK?

Replace

Q110

Replace

Q112

Replace

Q113

Is Q108 OK?

Replace

Q108

Is Q106 OK?

Replace

Q106

Replace IC104

Replace IC109 Replace L462

Is Q101 OK?

Is Q101 OK?

Is Q107 OK?

Replace

Q101

Replace

Q101

Replace

Q107

Replace IC108

Is Q105 OK?

Replace Q105

Replace BAT TERY

Replace F901

Replace LF101

NO

NO

YES

NO +5V_DAC

Check +12V

Replace IC120