Zenith XBV243 Schematic

SERVICE MANUAL

Model Series:

Product Type: VCR DVD Combo
Chassis: D35E Combo
Manual Series: VR168
Manual Part #: 923-03485
Model Line: E
Product Year: 2002

General Info ................................................. 1

Service Menu ................................................ 2

Servicing ..................................................... 3

Parts List ..................................................... 4

Diagrams ...................................................... 5

Schematics ................................................... 6

XBV243

CONTENTS

Published March 2002

by Technical Publications

Zenith Electronics Corporation

201 James Record Road

Huntsville, Alabama 35824-1513

Copyright  2002 by Zenith Electronics Corporation

PRODUCT SAFETY SERVICING GUIDELINES FOR AUDIO-VIDEO PRODUCTS

A

d

IMPORTANT SAFETY NOTICE

This manual was prepared for use only by properly trained audio-video service
technicians.

When servicing this product, under no circumstances should the original
design be modified or altered without permission from Zenith Electronics
Corporation. All components should be replaced only with types identical to
those in the original circuit and their physical location, wiring and lead dress
must conform to original layout upon completion of repairs.

Special components are also used to prevent x-radiation, shock and fire hazard.
These components are indicated by the letter “x” included in their component
designators and are required to maintain safe performance. No deviations are
allowed without prior approval by Zenith Electronics Corporation.

Circuit diagrams may occasionally differ from the actual circuit used. This way,
implementation of the latest safety and performance improvement changes into
the set is not delayed until the new service literature is printed.

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 property damage
or user injury.

Service work should be performed only after you are thoroughly familiar with
these safety checks and servicing guidelines.

GRAPHIC SYMBOLS

The exclamation point within an equilateral triangle is intended
to alert the service personnel to important safety information in
the service literature.

The lightning flash with arrowhead symbol within an equilateral
triangle is intended to alert the service personnel to the presence
of noninsulated “dangerous voltage” that may be of sufficient
magnitude to constitute a risk of electric shock.

The pictorial representation of a fuse and its rating within an
equilateral triangle is intended to convey to the service personnel
the following fuse replacement caution notice:
CAUTION: FOR CONTINUED PROTECTION AGAINST RISK OF FIRE,
REPLACE ALL FUSES WITH THE SAME TYPE AND RATING AS MARKED
NEAR EACH FUSE.

SERVICE INFORMATION

While servicing, use an isolation transformer for protection from AC line shock.
After the original service problem has been corrected, make a check of the
following:

FIRE AND SHOCK HAZARD

1. Be sure that all components are positioned to avoid a possibility of
adjacent component shorts. This is especially important on items trans­ported to and from the repair shop.

2. Verify that all protective devices such as insulators, barriers, covers,
shields, strain reliefs, power supply cords, and other hardware have been
reinstalled per the 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 or damaged insulation (including the AC cord), and
replace if necessary.

5. No lead or component should touch a high current device or a resistor
rated at 1 watt or more. Lead tension around protruding metal surfaces
must be avoided.

6. After reassembly of the set, always perform an AC leakage test on all exposed
metallic parts of the cabinet (the channel selector knobs, antenna terminals,
handle and screws) to be sure that set is safe to operate without danger of
electrical shock. DO NOT USE A LINE ISOLATION TRANSFORMER DURING THIS
TEST. Use an AC 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 150V AC type capacitor between a known good earth ground
water pipe, conduit, etc.) and the exposed metallic parts, one at a time.
Measure the AC voltage across the combination of 1500 ohm resistor and
.15 mfd capacitor. Reverse the AC plug by using a non-polarized adaptor
and repeat AC voltage measurements for each exposed metallic part. Voltage
measured must not exceed 0.75 volts RMS. This corresponds to 0.5 milliamp
AC. Any value exceeding this limit constitutes a potential shock hazard and
must be corrected immediately.

.C. Voltmeter

Good Earth Ground
such as the Water
Pipe, Conduit, etc.

0.15uF

1500 OHM

10 WATT

Place this probe
on each expose
metal part.

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 TV
receivers is the picture tube. However, this tube does not emit x-rays when
the HV 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 CRT anode connectors must be used.

3. It is essential that the service personnel have available an accurate and
reliable high-voltage meter.

4. When the high-voltage circuitry is operating properly, there is no possibility
of an x-radiation problem. Every time a 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.

5. When troubleshooting and making test measurements in a product with a
problem of excessively high voltage, avoid being unnecessarily close to
the picture tube and the high voltage power supply. Do not operate the
product longer than necessary to locate the cause of excessive voltage.

6. Refer to the CRT Anode High Voltage Measurement and Shutdown Adjustment
procedures described in the appropriate text (where used).

IMPLOSION

1. All direct view picture tubes are equipped with an integral implosion
protection system; take care to avoid damage during installation.

2. Use only the recommended factory replacement tubes.

TIPS ON PROPER INSTALLATION

1. Never install any receiver in a closed-in recess, cubbyhole, or closely
fitting shelf space over, or close to, a 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 placement where draperies may obstruct venting. The customer
should also avoid the use of decorative scarves or other coverings that
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 tests on customized installations.

5. Caution customers against mounting a product on a sloping shelf or in a
tilted position, unless the receiver is properly secured.

6. A product on a roll-about cart should be stable in 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 using a cart or stand that has not been listed
by Underwriters Laboratories, Inc. for use with its specific model of
television receiver or generically approved for use with TVs of the same or
larger screen size.

8. Caution customers against using extension cords. Explain that a forest of
extensions, sprouting from a single outlet, can lead to disastrous
consequences to home and family.

VR168 - 923-03485 D35E COMBO - SAFETY

i

TABLE OF CONTENTS

SECTION 1 SUMMARY 1-1

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

KEY TO ABBREVIATIONS ................................1-2

SERVICING PRECAUTIONS ..............................1-3

PACKAGE CONTENTS .....................................1-4

SECTION 2 CHASSIS 2-1

CABINET .................................................... 2-1

EXPLODED DIAGRAM .....................................2-1

SELF DIAGNOSTICS .......................................2-2

CABINET DISASSEMBLY ................................. 2-3

CIRCUIT BOARD DISASSEMBLY........................2-4

SECTION 3 ELECTRICAL 3-1

DVD TROUBLESHOOTING ................................ 3-1

VCR TROUBLESHOOTING .............................. 3-17

SECTION 4 MECHANICAL 4-1

VCR DECK MECHANISM .................................. 4-1

VCR ALIGNMENT ........................................ 4-13

MAINTENANCE/INSPECTION PROCEDURE ......... 4-19

VCR MECHANISM TROUBLESHOOTING ............. 4-23

DVD DECK MECHANISM ............................... 4-29

MECHANISM DISASSEMBLY........................... 4-30

DECK MECHANISM ADJUSTMENT ................... 4-32

SECTION 5 PARTS 5-1

COMPONENT PARTS .......................................... 5-2

SECTION 6 DIAGRAMS 6-1

EXPLODED VIEW ........................................... 6-1

VCR EXPLODED VIEW .....................................6-2

DVD EXPLODED VIEW ..................................... 6-3

MAIN BLOCK DIAGRAM ..................................6-4

POWER BLOCK DIAGRAM ................................ 6-5

TUNER-IF BLOCK DIAGRAM.............................6-6

Y/C BLOCK DIAGRAM ..................................... 6-7

AUDIO BLOCK DIAGRAM ................................. 6-8

HIFI BLOCK DIAGRAM ................................... 6-9

SYSTEM BLOCK DIAGRAM ............................. 6-10

SECTION 7 SCHEMATICS 7-1

POWER SUPPLY CIRCUIT ................................7-1

TUNER/IF CIRCUIT ....................................... 7-2

AV CIRCUIT ................................................. 7-3

HIFI CIRCUIT ..............................................7-4

SYSTEM CIRCUIT .......................................... 7-5

DVD CIRCUIT ...............................................7-6

DRIVE RF CIRCUIT ........................................ 7-7

MPEG CIRCUIT .............................................7-8

AUDIO CIRCUIT............................................7-9

MICRO CIRCUIT.......................................... 7-10

JACKPACK CIRCUIT ..................................... 7-11

VCR PCB LAYOUT ........................................ 7-12

DVD PCB LAYOUT TOP.................................. 7-13

DVD PCB LAYOUT BOTTOM ............................ 7-14

OTHER PCB LAYOUTS ................................... 7-15

WAVEFORMS .............................................. 7-16

VR168 - 923-03485 D35E COMBO - TOC

TOC-1

- TOC-2 -

section 1 SUMMARY

SUMMARY

SPECIFICATIONS

DVD PART

Power supply ........................................ AC 120 V, 60 Hz

Power .................................................. 23 W

Mass .................................................... 3.0kg(6.6lbs)

External dimensions .............................. 430 x 88 x 247 (W x H x D)

Signal system ....................................... PAL 625/50, NTSC 525/60

Laser ................................................... Semiconductor laser, wavelength 650nm

Frequency range ................................... (digital audio) 4 Hz to 20 kHz

Signal-to-noise ratio ............................. (digital audio) More than 100 dB (EIAJ)

Audio dynamic range ............................. (digital audio) More than 95 dB (EIAJ)

Harmonic distortion .............................. (digital audio) 0.008%

Wow and flutter ....................................Below measurable level (less than +0.001% (W.PEAK) (EIAJ)

Operating Temperature ........................... 5°C (41°F) to 35°C (95°F)

OUTPUTS

Video outputs ...................................... 1.0V (p-p), 75., negative sync., RCA jack x 1

S video outputs .................................... (Y) 1.0V (p-p), 75., negative sync.,Mini DIN 4-pin x 1

(C)0.3V(p-p), 75.

Component video .................................. output (Y) 1.0 V (p-p), 75 ., negative sync., RCA jack x 1

(Pb)/(Pr) 0.7 V (p-p), 75 .

Audio output ....................................... (digital audio) 0.5V (p-p), 75., RCA jack X 1

Audio output ....................................... (optical audio) Optical connector x 1

Audio output ....................................... (analog audio) 2.0Vrms (1kHz,0dB), RCA jack (L,R) x 1

VHS PART

Video Head System ................................ Double azimuth 4 heads, helical scanning

RF Modulator........................................ UHF 28-68 (Adjustable)

Tape format .......................................... Tape width 12.7 mm (0.5 inch)

Timer ................................................... 24 hours display type

*Designs and specifications are subject to change without notice.
*Weight and dimensions shown are approximate.

VR168 - 923-03485 1-1 D35E COMBO - SUMMARY

KEY TO ABBREVIATIONS

A

AC
ACC
ADJ
A/E
AFC
AFT
AGC Automatic Gain Control
ALC
AM
AMP
ANT
APC
ASS’Y
AUD
AUTO
AUX

B

B

C

BPF
BW or B/W

C
CAN
CAP
CATV
CBA
CCD
CFG
CH
CHROMA
CLK
CNR
COMB

COMP

CONV
CS
CST
CTL
CUR
CYL

D
dB
DC
DEMOD
DET
DEV
DHP
DIGITRON
DL
DOC
D/V

E
EE
EMP
EP
EQ
ES

F
FB
FBC
FE
FF
FG
FL
FM
F/R
FS
FSC
F/V
FWD

GEN
GND

H
Hz

IC
IF
INS
I/O

L
LD
LECHA
LP
LPF

D

E

F

G

H

I

L

Alternating Current
Automatic Color Control
Adjust
Audio Erase
Automatic Frequency Control
Automatic Fine Tuning

Automatic Level Control
Amplitude Modulation
Amplifier
Antenna
Automatic Phase Control
Assembly
Audio
Automatic
Auxiliary

Base
Bandpass Filter
Black and White

Capacitor, Chroma, Collector
Cancel
Capstan
Cable Television
Circuit Board Assembly
Charge Coupled Device
Capstan Frequency Generator
Channel
Chrominance
Clock
Chroma Noise Redution
Combination

Comb Filter

Comparator

Composite

Compensation
Converter
Chip Select
Cassette
Control
Current
Cylinder

Drum, Digital, Diode, Drain
Decibel
Direct Current
Demodulator
Detector
Deviation
Double High Pass
Digital Display Tube
Delay line
Drop Out Compensator
Dummy Vertical

Emitter
Electric to Electric
Emphasis
Extended Play
Equalizer
Electrostatically Sensitive

Fuse
Feed Back
Feed Back Clamp
Full Erase
Fast Forward
Frequency Generator
Filter
Frequency Modulation
Front/Rear
Frequency Synthesizer
Subcarrier Frequency
Frequency Voltage
Forward

Generator
Ground

High, Horizontal
Hertz

Integrated Circuit
Intermediate Frequency
Insert
Input/Output

Low, Left, Coil
LED
Letter Character
Long Play
Low Pass Filter

SUMMARY

M

MAX
MD
MIC
MIN
MIX
MM
MMV
MOD
MODEM

NR
OSC

OSD
PB

PCB
PG
PLL
P. P
PRE-AMP
PS
PWM

Q
QH
QSR
QTR
QV

R
RE(or RC)
REC
REF
REG
REMOCON
REV
REW
RF
R/P
RTC

S
SH
SHARP
SIF
SLD
S/N
SP
SUB
SW or S/W
SYNC
SYSCON

T
TP
TR
TRK
TRANS
TU

UHF
UNREG

V
VA
VCO
VGC
VHF
VISS
VR
V-SYNC
VTG
VV
VXO

W
WHT
W.O

X-TAL
Y/C

YNR

ZD

N
O

P

Q

R

S

T

U

V

W

X
Y

Z

Maximum
Modulator
Microphone
Minimum
Mixer, Mixing
Monostable, Multivibrator
Mono Multi Vibrator
Modulation, Modulator
Modulator-Demodulator

Noise Reduction
Oscillator

On Screen Display
Playback

Printed Circuit Board
Pulse Generator
Phase Locked Loop
Peak-to-Peak
Preamplifier
Phase Shift
Pulse Width Modulation

Transistor
Quasi Horizontal
Quick Setting Record
Quick Timer Record
Quasi Vertical

Resistor, Right
Remocon, Receiver
Recording
Reference
Regulated, Regulator
Remote Control(unit)
Reverse
Rewind
Radio Frequency
Record/Playback
Reel Time Counter

Serial
Shift
Sharpness
Sound Intermediate Frequency
Side Locking
Signal to Noise Ratio
Standard Play
Subtract, Subcarrier
Switch
Synchronization
System Control

Coil
Test Point
Transistor
Tracking
Transformer
Tuner,Take-up

Ultra High Frequency
Unregulated

Volt, Vertical
Always Voltage
Voltage Controlled Oscillator
Voltage Gain Control
Very High Frequency
VHS Index Search
Variable Resistor or Volume
Vertical Synchronization
Voltage
Voltage to Voltage
Voltage X-tal Oscillator

Watt
White
With out

Crystal
Luminance/Chrominance

Luminance Noise Reduction

Zener Diode

VR168 - 923-03485 1-2 D35E COMBO - SUMMARY

SUMMARY

SERVICING PRECAUTIONS

CAUTION: Before servicing the product covered by this
service data and its supplements and addends, read and
follow the SAFETY PRECAUTIONS.

NOTE: if unforeseen circumstances create conflict between

the following servicing precautions and any of the
safety precautions in this publication, always follow
the safety precautions.

GENERAL SERVICING PRECAUTIONS

1. Always unplug the product AC power cord from the
AC power source before:

(1) Removing or reinstalling any component, circuit

board, module, or any other assembly.

(2) Disconnecting or reconnecting any internal elec-

trical plug or other electrical connection.

(3) Connecting a test substitute in parallel with an

electrolytic capacitor.

CAUTION: A wrong part substitution or incorrect polarity

installation of electrolytic capacitors may result in
an explosion hazard.

2. Do not spray chemicals on or near this product or
any of its assemblies.

3. Unless specified otherwise in this service data, clean
electrical contacts by applying an appropriate con­tact cleaning solution to the contacts with a pipe
cleaner, cotton-tipped swab, or comparable soft ap­plicator. Unless specified otherwise in this service
data, lubrication of contacts is not required.

4. Do not defeat any plug/socket B+ voltage interlocks
with which instruments covered by this service
manual might be equipped.

5. Do not apply AC power to this product and/or any of
its electrical assemblies unless all solid-state device
heat sinks are correctly installed.

6. Always connect the test instrument ground lead to
the appropriate ground before connecting the test
instrument positive lead. Always remove the test in­strument ground lead last.

INSULATION CHECKING PROCEDURE

Disconnect the attachment plug from the AC outlet and
turn the power on. Connect an insulation resistance meter
(500V) to the blades of the attachment plug. The
insulation resistance between each blade of the
attachment plug and accessible conductive parts should
be more than 1Mohm. Accessible conductive parts
include metal panels, input terminals, earphone jacks,
etc.

ELECTROSTATICALLY SENSITIVE (ES) DEVICES

Some semiconductor (solid state) devices can be
damaged easily by static electricity. Such components
commonly are called Electrostatically Sensitive (ES)
Devices. Examples of typical ES devices are integrated
circuits and some field effect transistors and
semiconductor chip components. The following
techniques should be used to help reduce the incidence
of component damage caused by static electricity.

1. Immediately before handling any semiconductor com­ponent or semiconductor-equipped assembly, drain
off any electrostatic charge on your body by touch­ing a known earth ground. Alternatively, obtain and
wear a commercially available discharging wrist strap
device, which should be removed for potential shock
reasons prior to applying power to the unit under
test.

2. After removing an electrical assembly equipped with
ES devices, place the assembly on a conductive sur­face such as aluminum foil, to prevent electrostatic
charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or
unsolder ES devices.

4. Use only an anti-static solder removal device. Some
solder removal devices not classified as “anti-static”
can generate electrical charges sufficient to damage
ES devices.

5. Do not use freon-propelled chemicals. These can gen­erate an electrical charge sufficient to damage ES
devices.

6. Do not remove a replacement ES device from its pro­tective package until immediately before you are
ready to install it. (Most replacement ES devices are
packaged with leads electrically shorted together by
conductive foam, aluminum foil, or comparable con­ductive material).

7. Immediately before removing the protective mate­rial from the leads of a replacement ES device, touch
the protective material to the chassis or circuit as­sembly into which the device will be installed.

Caution: Be sure no power is applied to the chassis or circuit,

and observe all other safety precautions.

8. Minimize bodily motions when handling unpackaged
replacement ES devices. (Normal harmless motion such
as the brushing together of your clothes fabric or
the lifting of your foot from a carpeted floor can
generate static electricity sufficient to damage an
ES device.)

VR168 - 923-03485 1-3 D35E COMBO - SUMMARY

PACKAGE CONTENTS

SUMMARY

BATTERY

REMOCON

PACKING

CABLE SET ASS'Y

RF CABLE

PHONO CORD 1WAY

PHONO CORD 2WAY

OWNER'S MANUAL

PAC KIN G S HE ET

PAC KI NG

BOX CARTON

OPTIONAL PARTS

VR168 - 923-03485 1-4 D35E COMBO - SUMMARY

section 2 CHASSIS

Angle icon indi

s

CABINET

FRONT

DISPLAY

CHASSIS

BACK

Repeat playback
mode indicators

Stereo indicator

DVD indicator

Video CD indicator

AB

VCD
DVD

ST

ALL MP3

-R W
BIL PR
SAP CH

cator

PROGRAM indicator

Title number indicator

CD REC indicator

AM
SP
LP
EP

Total playing time/elapsed time indicator

Chapter/Track number indicator

EXPLODED DIAGRAM

See page 6-1 for a detailed exploded view.

VR168 - 923-03485 2-1 D35E COMBO - CHASSIS

CHASSIS

SELF DIAGNOSTICS

SELF DIAGNOSTIC OVERVIEW

Provides service personnel a convenient service aid by a
visual display of error codes generated by the
microcomputer and displayed on the digitron.

OPERATIONAL PROCEDURE

With the remote control, press and hold the “MENU” key
until the word MENU appears in the display. Then press
4, 3, 2, 1 and then “ENTER”. The self diagnostic procedure
will sequence through the 8 step procedure. If an error
is detected, a code number will flash approximately 5
times and then return to its initial mode of operation.

DISPLAY

“D1”

“D2”

DESCRIPTION INPUT SIGNAL CIRCUIT STATUS SERVICE POINTS

•Tape Loading
Error

•Tape Loading

Error

•Mode SW
Pos. S1, S2, S3, S4
Pins: 25, 24, 23, 22

•Load Motor
Pins: 60 (+)
Pins: 59 (-)

•Mode SW
Pos. S1, S2, S3, S4
Pins: 25, 24, 23, 22

•Load Motor
Pins: 60

NOTES

1. Error codes will not be stored. The program must be
re-initialized as described in the preceding step.

2. Pin numbers refer to IC501 microcomputer, unless
otherwise stated.

•Mode SW Position not
changed within 6 seconds
after cassette loading
attempt.

•Mode SW Position not
changed within 6 seconds
after cassette loading
attempt.

•Loading motor,
mech problems,
gears, timing

•Mode SW Position

•Mode SW Contacts

“D3”

“D4”

“D5”

“D6”

“D7”

“F1”

•CST Loading
Error

•CST Loading
Error

•DRUM Motor
Error

•Reel Rotational

Error

•Capstan Motor
Error

•Tuner Signal
Input

•Mode SW
Pos. S1, S2, S3, S4
Pins: 25, 24, 23, 22

•Load Motor
Pins: 60

•Mode SW
Pos. S1, S2, S3, S4
Pins: 25, 24, 23, 22

•Load Motor
Pins: 60

•Head SW(30Hz)
Pulses Pin18

•Supply Take-up Reel
Pulses, Pins 79, 80

•Capstan FG Pulses

•CVin Pin 56

•Mode SW Position not
changed within 6 sec­onds after cassette
loading attempt.

•CST SW must be activat­ed within 3 seconds, oth­erwise unit shut down will
occur.

•Drum Motor (Slow Start)

•Motor must be up to
speed within 3 seconds
of operation

•CFG Signal present, but
take-up pulses are mis­sing.
(Capstan motor running)

•No CFG Signal

•Composite Sync not
detected, RF or Video

Signal loss.

•Mode SW Contacts

•CST SW or
Connector Contacts

•Drum Motor and
Control Circuits

•Capstan belt

•Idler and reel gears
damaged

•ST/U Sensors

•Capstan control ckt.

•Motor assy.

•IC501 Ckt.

•Loss of C-sync
Tuner Line
Video Path

VCR should be in PB mode for D5, D6 and D7. Stop mode for F1, cassette loading D3, D4 and tape loading D1 and D2.

VR168 - 923-03485 2-2 D35E COMBO - CHASSIS

CHASSIS

CABINET DISASSEMBLY

CAUTION BEFORE SERVICING

Electronic parts are susceptible to static electricity and
may easily be damaged. Follow proper grounding
procedures.

Many screws are used inside the unit. To prevent missing,
dropping, etc. of the screws, always use a magnetized
screw driver in servicing. Several kinds of screws are used
and some of them need special cautions. That is, take
care of the tapping screws securing molded parts and
fine pitch screws used to secure metal parts. If they are
used improperly, the screw holes will be easily damaged
and the parts can not be fixed.

CABINET DISASSEMBLY

TOP CASE

1. Remove 7 screws (A). (See Fig. 2-1)

2. Pull the top case back and up, in the direction of
the arrow, to disengage it from the front panel.

Fig. 2-2

FRONT PANEL

1. Eject the disc tray. (See Fig. 2-2)

2. Remove the tray door. (See Fig. 2-2)

3. Depress the 7 embossed tabs (see fig. 2-3) and
remove the Front panel.

Tabs

Fig. 2-1

Tabs

TRAY DOOR

1. Eject the disc tray.

2. Lift up the tray door in the direction of the arrow.

VR168 - 923-03485 2-3 D35E COMBO - CHASSIS

Fig. 2-3

Tab

CHASSIS

CIRCUIT BOARD DISASSEMBLY

Note: Before removing the main circuit board, be sure

to short circuit the laser diode output land. After
replacing the main circuit board, open the land after
inserting the flexible connector.

MAIN CIRCUIT BOARD AND INTERFACE BOARD

1. Remove the top case. (See Fig. 2-1)

2. Remove 14 screws (B).

3. Remove the Deck from the Main Circuit Board.

4. Remove the Main Circuit Board from the Interface
Board.

5. Remove 2 screws (C).

6. Remove the Interface Board from the chassis.

DIGITRON AND KEY CIRCUIT BOARD

1. Remove the front panel. (See Fig. 2-3)

2. Release 3 screws (D), and remove the digitron cir­cuit board.

Fig. 2-5

Fig. 2-4

VR168 - 923-03485 2-4 D35E COMBO - CHASSIS

SECTION 3 Electrical

T

TROUBLESHOOTING

1. Power(SMPS) CIRCUI

ELECTRICAL

(1) No 5.3VA (SYS/Hi-Fi/TUNER)

NO 5.3VA.

YES

Is F101 normal?

YES

Is R101

normal?

YES

Is Bd101

normal?

YES

Is Vcc (8.5~21V)

supplied to IC101 Pin7?

YES

NO

NO

NO

NO

Replace F101.

Replace

BD101.

Replace R101.

Is D102

normal?

N O

(2) No 12VA (TO CAP, DRUM MOTOR)

NO 12VA.

YES

Is the Vcc (13V) supplied to (+)

terminal in D115 and D117?

YES

Is the Vcc (12V) supplied to (-)

terminal in D115 and D117?

YES

Check or Replace

the Motor Vcc.

NO

NO

Check or Replace

D110.

Replace D115,

Is the D112 normal?

YES

Is there about 2.5V

at the IC102 Vref?

YES

Is D110 normal?

YES

Check the Main PCB

5.3VA/5.0V Line short?

Check or Replace

D102.

(3) No 5.2V (SYS/Hi-Fi/TUNER)

N O

N O

N O

Replace D112.

Replace IC102.

Replace the D110.

NO 5.2VA.

YES

Is 5.3VA put into

Q116 Emitter?

YES

Is Q115 Base

“H”?

YES

Is about 5V put into

Q116 Base?

YES

Check or Replace

Q115/Q116

NO

NO

NO

5.3VA Line Check.

Check the Power

Control.

Check or Replace Q115,

R160, R161, R162, D122.

VR168 - 923-03485 3-1 D35E COMBO - ELECTRICAL

TROUBLESHOOTING (CONTINUED)

ELECTRICAL

(4) No 5V (TO DVD)

NO 5V.

YES

Is 5.3VA present on

Q113 Emitter?

YES

Is the Q115 Base

“H”?

YES

Is about 5V present on

Q113 Base?

YES

Check or Replace

Q113/Q115

NO

NO

NO

5.3VA Line Check.

Check the Power

Control.

Check or Replace

Q115, R157, R158,

R159, D121.

(5) No REG 5V (AVCP)

No REG 5V.

YES

Is 5.3VA present on

Q117 Collector?

YES

Is 33V present on

Q117 Base?

YES

Check or Replace Q117,

R167, ZD105, C162.

NO

NO

5.3VA Line Check.

Check 33V Line.

(6) No 33V (TUNER)

No 33V.

YES

Is Q115 Base “H”?

YES

Check or Replace

Q114, R154, R155.

(7) No REG 12V

No REG 12V.

YES

N O

Check the Power

Control.

Is 13V present on

Q112 Collector?

YES

Is 33V present on

Q112 Base?

YES

Check or Replace Q112,

ZD103, R153, C151.

NO

NO

Check or Replace

D110.

Check 33V Line.

VR168 - 923-03485 3-2 D35E COMBO - ELECTRICAL

(8)

TROUBLESHOOTING (CONTINUED)

No -29VA.

ELECTRICAL

(9) No 8VA

No -29VA.

YES

Check or Replace

D108.

(10) No 3.3VA

NO 8VA.

YES

Is Vcc (13V) supplied to

(+) terminal in D114?

YES

Is Vcc (12V) supplied

to IC106 Pin1?

YES

Is Q115 Base

“H”?

YES

Check or Replace

IC106, R170, C154.

(11) No 2.5V

NO

NO

NO

Check or Replace

D110.

Check or Replace

D114.

Check the Power

Control.

No 3.3V

YES

Is Vcc (4V) supplied

to IC103 Pin1?

YES

Is the Q115 Base

“H”?

YES

Check or Replace

IC103, R156, C153.

NO 2.5VA.

YES

N O

N O

Check or Replace

D111.

Check the Power

Control.

Is Vcc (4V) supplied

to IC104 Pin1?

YES

Is the Q115 Base

“H”?

YES

Is Vcc (3.3V) supplied

to IC104 Pin2?

YES

Check or Replace

D119, C159.

NO

NO

NO

Check or Replace

D111.

Check the Power

Control.

Check or Replace

Ic104.

VR168 - 923-03485 3-3 D35E COMBO - ELECTRICAL

TROUBLESHOOTING (CONTINUED)

2. SYSTEM/KEY CIRCUIT
(1) AUTO STOP

Auto Stop

YES

ELECTRICAL

Does the SW30 waveform

appear at IC501

Pin24?

YES

Do the T-UP Reel Pulses

appear at IC501 Pin4?

YES

Replace Ic501.

(2) The unstable loading of a Cassette tape

The unstable loading of a

Cassette tape

YES

Is 12V applied to

PMC01 Pin8?

YES

NO

NO NO

O

N

Check the Drum Motor

signal.

Do T/UP Reel Pulses

appear at Q514
Base terminal ?

YES YES

Replace the T/UP Reel

Sensor (RS501).

12 Volt Trouble Shooting”.

Does 5.2V appear at

RS501?

NO

Check the Q116 Power

Circuit.

Refer to “SMPS DRUM

Does the “H” signal appear

at Ic501 Pin57 during

inserting the CST ?

YES

Does the “L” signal appear

at Ic501 Pin19 during

inserting the CST?

YES

Check the Deck

Mechanism.

Caution: Auto stop can occur because Grease or Oil is dried up

VR168 - 923-03485 3-4 D35E COMBO - ELECTRICAL

O

NO

N

Check the CST SW and
the peripheral circuitry.

Is 5.3V applied to

R544 ?

YES

Refer to SMPS 5.3VA

troubleshooting.

Check IC501

Pins74, 75, 76, 77.

NO

TROUBLESHOOTING (CONTINUED)

3. SERVO CIRCUIT
(1) Unstable Video in PB MODE

Unstable Video in

PB Mode.

YES

Does the Noise level of the

screen change periodically?

YES

ELECTRICAL

Do the CTL pulses appear

at IC501 Pin37?

Does the CFG waveform

appear at IC501

On tracking do the CTL

pulses move?

Does the Video Envelope

waveform appear at

IC501 Pin12?

Replace 501.IC

(2) When the Drum Motor

doesn’t run.(2)

When the Drum Motor

Does 12V appear at

PMC01 Pin8?

Does 2.8V appear at

PMC01 Pin12?

Check the connector

(PMC01) and the Drum

Motor Ass’y.

YES

Pin40?

YES

YES

YES

doesn’t run,

YES

YES

NO

NO

NO

O

O

Is the adjustment height of

the CTL Head accurate?

Replace 501.IC

Refer to “When the Y signal

doesn’t appear on the

screen in PB Mode”.

Refer to “(2)

No 12VA of Power section”

Do the Drum PWM Pulses

appear at 501

Are the foil patterns and

the Components between

IC501 Pin26 and PMC01

Pin12 short?

Do the DFG Pulses appear

at the IC501 Pin38?

N

Do the Drum PWM Pulses

appear at 501

N

IC

Pin26?

YES

YES

IC

Pin26?

YES

NO

NO

NO

NO

Readjust the height of the

CTL Head

Do the DFG Pulses appear

at PMC01 Pin11?

YES

NO

Replace the Cap M.

Aren’t the foil patterns and

the Components between
IC501 Pin 38 and PMC01

Pin11 short?

Replace 501.IC

Are the connecting patterns and the Components
between IC501 Pin26 and PMC01 Pin11 short?

VR168 - 923-03485 3-5 D35E COMBO - ELECTRICAL

TROUBLESHOOTING (CONTINUED)

(3) When the Capstan Motor doesn’t run

When the Capstan Motor doesn’t run,

ELECTRICAL

Does 12VA appear at PMC01?

YES

Does 2.8V appear at PMC01?

YES

Check PMC01 and the Capstan

Motor Ass’y.

Are the foil patterns and Components

between IC501 Pin25 and PMC01

Pin9 short?

Does the CFG signal come into

IC501 Pin40?

NO

NO

YES

YES

Refer to “SMPS (CAPSTAN/12Volt)

Trouble Shooting”.

Does the PWM signal appear at

IC501 Pin25?

NO

Does the CFG signal appear at

PMC01 Pin1?

NO

Check the Capstan Motor Ass’y.

N O

YES

Does the Capstan PWM signal appear at

IC501 Pin25?

N O

YES

Are the foil patterns and Components

between IC501 Pin 25 and PMC01

Pin9 short?

VR168 - 923-03485 3-6 D35E COMBO - ELECTRICAL

Are the foil patterns and component

between IC501 Pin40 and PMC01

Pin1 short?

Replace IC501.

TROUBLESHOOTING (CONTINUED)

KEY doesn't work.

(3)

KEY doesn’t work.

ELECTRICAL

Is 5V applied to

IC501 Pin 15?

YES

Does LED or FLD change

when a function button is

pressed?

4. OSD CIRCUIT

1) No OSD display.

No OSD display.

Is 5.3V applied to

IC501 Pin 42?

YES

Does oscillation occur at

IC501 Pins 52, 53?

YES

Does oscillation occur at

IC501 Pins 50, 51?

YES

Replace IC501.

NO

NO

NO

NO

O

Refer to “SMPS 5.3VA

Trouble Shooting”.

Replace the defective

Refer to “SMPS 5.3VA

Trouble Shooting”.

Is the oscillation input to

Q501 base?

Check or Replace the
Peripheral Circuitry. (L506,
R517, C519, C518, R518)

N

(3) I2C BUS CHECK

switches.

NO

YES

Check whether X301

oscillates

Check or Replace the
Peripheral Circuitry. (L506,
R517, C519, C518, R518)

The I2C waves don’t

2) No F.OSD display.

No F.OSD display.

Refer to “(1) No OSD

display”.

YES

Does the C.SYNC signal
appear at IC501 Pin87?

YES

Replace IC501.

VR168 - 923-03485 3-7 D35E COMBO - ELECTRICAL

O

N

Refer to “AVCP. C. Sync.

come out.

Does Power appear at

the Pull up impedence

Replace IC501.

Trouble shooting”.

(R508, R510)?

YES

NO

Refer to “SMPS 5.3VA

Trouble Shooting”.

DVD TROUBLESHOOTING (CONTINUED)

5. Y/C CIRCUIT

(1) No Video in EE Mode

No Video in EE Mode

ELECTRICAL

Does the Video signal

appear at IC301

Pins28, 30, 31?

YES

Is 5.2V applied to IC301

Pins12, 36, 61, 67, 90, 96?

YES

Does the Video signal

appear at IC301 Pin 52?

YES

Does the Video signal

appear at IC501 Pin 45?

YES

Does the Video signal

appear at the Emitter

terminal of Q801?

Check DVD Video Input (IC802, Pin29), Tuner Video Input
(TU701 Pin24), Line Video Input (JK801), respectively.

Check the REG 5V Line.

(Power Circuit)

Is I2C BUS signal applied to

IC301 Pins 62, 63?

YES

Check the path of the signal

between Ic301 Pin

52 and IC501 Pins 43, 45.

Is there 12V on the plus

terminal of C822?

YES

Check the System Circuit.

(Refer to ‘SYSTEM I2C BUS

CHECK Trouble Shooting’)

Check C330. (AGC)

Replace IC301.

YES

Replace Q801.

VR168 - 923-03485 3-8 D35E COMBO - ELECTRICAL

Check the REG 12V Line.

(Power Circuit)

ELECTRICAL

DVD TROUBLESHOOTING (CONTINUED)

(2) When the Y(Luminance) signal doesn’t appear on the screen in PB Mode

Is 5V applied to IC301

Pins 12, 36, 61, 67, 90, 96?

YES

Is the I2C Bus signal applied

to IC301 Pins 62, 63?

YES

Does the normal RF signal

appear at the IC301 Pin79?

YES

NO

NO

NO

Check the line of the REG

5V Line. (Power Circuit)

Refer to ‘SYSTEM I2C BUS

CHECK Trouble Shooting’.

Is the V.H.S/W signal

applied to IC301 Pin81?

YES

Does the Rectangular

waveform (5V) appear at

IC301 Pin81(V.H.S/W)

YES

Clean the Drum.

NO

NO

NO

Check the System Circuit.

(IC501 Pin24)

Check the V.H.S/W level.

Replace IC301.

Does the Y(Luminance)

signal appear at IC301

Pin18?

YES

Is the Y(Luminance) Video

waveform showed up at

IC301 Pin39?

YES

Replace IC301.

VR168 - 923-03485 3-9 D35E COMBO - ELECTRICAL

N O

N O

Check the path of the
Y(Luminance) signal.

Check the path of the

Y(Luminance) signal.

YES

YES

ELECTRICAL

Y/C

T

TROUBLESHOOTING (CONTINUED)

CIRCUI

(3) When the C(Color) signal doesn’t appear on the screen in PB Mode,

Is 5V applied to IC301

Pins 12, 36, 61, 67, 90, 96?

YES

Does Color signal appear
at the IC301 Pins 58, 60?

YES

Replace IC301.

NO

NO

Check the line of the REG

Does X301(3.58MHZ)

oscillate?

Does the Color signal

appear at IC301 Pin55?

Check the circuit of

IC301 Pins 60, 58, 35.

5V Line. (Power Circuit)

NO

NO

YES

Replace X301.

Check the Color Pass.

(Check C341)

Replace IC301.

VR168 - 923-03485 3-10 D35E COMBO - ELECTRICAL

ELECTRICAL

(4)

TROUBLESHOOTING (CONTINUED)

When the Video signal doesn’t appear on the screen in REC Mode,

REC mode

YES

Is EE mode normal?

YES

Is brightness ?

YES

Is the brightness signal

supplied to IC301 Pins 13,14?

YES

Check the power of Pins 12,

36, 61, 67, 90, 96.

YES

Check the REG 5V power

Does the brightness signal

appear at IC301 Pins 21, 26?

YE SNO

NO

YES

NO

NO

NO

Check the EE mode

Is color?

Is color?

NO

Does signal appear at

IC301 Pins 58, 60?

YES

Is 5V supplied to IC301

Pins 12, 36, 61, 90, 96?

YES

Is I2C Bus applied to

IC301 Pins 62, 63?

Do X301, 302 and X-TAL

YES

oscillate?

NO

NO

NO

Check the 5V power

Check system part

Check X301, 302

Is I2C Bus applied to IC301

Pins 62, 63?

YES

Is V.H SW supplied to

IC301 Pin81?

YES

Does the FM signal appear

at IC301 Pins 87, 88(SP)/

92, 93(EP)?

YES

Check the drum

VR168 - 923-03485 3-11 D35E COMBO - ELECTRICAL

NO

NO

NO

Check system part

Check system part

(V.H/SW)

Replace IC301.

*OPTION
Pins86, 87, 88, 89(SP)
Pins91, 92, 93, 94(EP)

CIRC

TROUBLESHOOTING (CONTINUED)

6. Hi-Fi

(A) No Sound(EE Mode)

UIT

No Sound.

YES

ELECTRICAL

Check the TU Audio of IC801

Pins 1, 3

Check the DVD Audio of IC801

Pins 4, 5.

Check the AV1 Audio of IC801

Pins 6, 7.

Check the AV2 Audio of IC801

Pins 10, 11.

Check the Vcc of IC801 Pins 34, 40,

IC802 Pin 4.

YES

NO

NO

NO

NO

YES

N O

Check IC751 Pins 30, 31.

Check the DVD MODULE.

(P8D01 Pins 3, 5).

Check the Rear Jack.

(JK801 Audio in).

Check the front Jack.

(PM401 Pins 1, 2).

Check the Power 5.2V, 12V.

Check the IIC Clock and DATA at

IC801 Pins 42, 43, IC802 Pins 32, 33.

N O

Check IC501 Pins 90, 91.

YES

N O

Check the Audio of IC801 Pins 16, 17.

Replace IC801.

YES

Check the Audio of IC802 Pins 22, 26.

N O

Replace IC802.

YES

Check JK801.

VR168 - 923-03485 3-12 D35E COMBO - ELECTRICAL

TROUBLESHOOTING (CONTINUED)

3. Y/C CIRCUIT

(B) Hi-Fi Playback

PB mode

YES

No Sound.

YES

ELECTRICAL

Check the Vcc of IC801

(Pins 34, 40)

YES

Check the Hi-Fi Selection switch.

(IC801 Pin 41) and the Tape quality.

YES

Is the RF Envelope at

IC801 Pin 44 over 2Vp-p?

YES

Check IC801 Pin42(Data),

Pin 43(Clock)

YES

Do Audio Signals appear at

IC801 Pin16(L-CH), 17(R-CH)?

YES

Do Audio Signals appear at

IC802 Pin10(L-CH), 16(R-CH)?

YES

NO

NO

NO

NO

Check Power.

Check IC501 Pin23

(A.H/SW)

Check the parts of µ-COM

(IC501 Pins90, 91)

N O

N O

Check the Connection at

P3D01 Pins 7, 9.

Check the A.IN line of

IC802 (C828, C829)

Do Audio Signals appear at

IC802 Pins 22, 26?

YES

Do Audio Signals appear at

JK801?

N O

Check the Vcc of IC802

Pin 4.

YE S YES

Replace IC802.

N O

Check Jack(JK801)

NO

Check Power.

YES

Do Audio Signals appear at

TU701 Pin 2 (MOD A.IN)?

VR168 - 923-03485 3-13 D35E COMBO - ELECTRICAL

N O

Check IC405.

(C)

TROUBLESHOOTING (CONTINUED)

Hi-Fi REC.

YES

It is impossible to record Hi-Fi Audio

signal.

YES

ELECTRICAL

Check Vcc of IC801.(Pins34, 40)

YES

Check IC801 Pin42(Data), Pin43(CLOCK).

YES

Do Audio signals appear at IC801

Pins16, 17?

YES

Do FM Audio signals appear at IC801

Pin36?

YES

Check the Contact Point of Drum

Connector if good then Replace the Drum.

NO

NO

NO

Check Power.

Check ports of µ-CPM.

Check Audio input signal of IC801

Pins2, 3(TU.A.), 4, 5(DVD.A.),

6, 7(AVI.A.), 10, 11(AV2.A.)

N O

Replace IC801.

VR168 - 923-03485 3-14 D35E COMBO - ELECTRICAL

TROUBLESHOOTING (CONTINUED)

7. Tuner/IF CIRCUIT

(A) No Picture on the TV screen

No picture on the TV

screen

YES

ELECTRICAL

Is the Video signal at

the TU701 Pin 24.

YES

Is +33V applied to TU701

Pin16?

YES

Is +5V applied to TU701

Pin13?

YES

Does the Clock signal

appear at TU701 Pin 11?

YES

Does the data signal

appear at TU701 Pin 12?

YES

Replace Tuner.

Check 33V line.

Check 5V line.

Check the lIC .Clock Signal

of µ-COM Pin90

Check the lIC Data Signal

of µ-COM Pin91.

Does Sync appear at

IC501 Pin 87.

Check the signal flow from

TU701 Pin24 to IC301 Pin 31.

YES

Does the Video signal at

IC501 Pin 45.

Check the signal from IC301

Pin52 to IC501 Pin 43.

YES

Does the Video signal at

IC802 Pin 30.

Check the signal from IC501

Pin45 to IC802 Pin 1.

YES

Check the signal flow from IC802

Pin 30 to JK801 Pin Video out.

VR168 - 923-03485 3-15 D35E COMBO - ELECTRICAL

(B)

TROUBLESHOOTING (CONTINUED)

No Sound

No Sound.

YES

ELECTRICAL

Check the Vcc of IC751 Pins1,

11, 19, 22, 33.

YES

Check the Tuner SiF signal at

IC751Pin2.

YES

Check the oscillator of IC751 Pins 5, 6.

YES

Check the Audio of IC751 Pins30, 31.

YES

Check the Audio of IC801 Pins 2, 3.

YES

NO

NO

NO

NO

Check 5.2V Line.

Check the Tuner SIF of TU701 Pin22.

Replace X751

Check the IIC Clock and Data at IC751

Pins 12, 13.

N O

Check the signal flow from IC751

Pins30, 31 to IC801 Pins 2, 3.

Check the Audio of IC801 Pins 16, 17.

N O

Check the IIC Clock and Data at IC801

Pins42, 43.

YES

N O

Check the Audio of IC802 Pins 22, 26.

Check the signal flow from IC801

Pins16, 17 to IC802 Pins 10, 16.

YES

Check the Signal flow from IC802 Pins22,

26, JK801 Audio out(L), (R)

VR168 - 923-03485 3-16 D35E COMBO - ELECTRICAL

1

COM Ci

TROUBLESHOOTING

ELECTRICAL

. µ-

A. Audio abnormal

rcuit

AUDIO ABNORMAL

Check Audio jack.

Check MPEG_CLK Signal

of MPEG part.

Refer to Audio part.

Refer to MPEG part.

Replace B/D.

YES

YES

YES

YES

(If OK)

(If OK)

(If OK)

(If OK)

B. Video abnormal

VIDEO ABNORMAL

Check Video jack.

Refer to Video part.

Refer to Encoder part.

Refer to MPEG part.

Replace B/D.

YES

YES

YES

YES

(If OK)

(If OK)

(If OK)

(If OK)

C. Open/Close abnormal

Check the connection of MD.

YES

OPEN/CLOSE ABNORMAL

connection of PMD03.

NO

Check IC501 Pins 13, 14.

Refer to SERVO part.

Check Front.

YES

Check the

YES

YES

(If OK)

NO

Reconnect it.

VR168 - 923-03485 3-17 D35E COMBO - ELECTRICAL

DVD TROUBLESHOOTING (CONTINUED)

D. Picture abnormal

PICTURE ABNORMAL

Check the disc.

Refer to Servo part

If OK

Check MPEG_CLK Signal

of MPEG part

YES

Check DSP

ELECTRICAL

(If OK)

E. Disc Error

Refer to Servo part

YES

Check MPEG

YES

Replace B/D

DISC ERROR

Check Disc

YES

YES

(If OK)

(If OK)

(If OK)

(If OK)

Replace B/D

VR168 - 923-03485 3-18 D35E COMBO - ELECTRICAL