Zenith GBV441 Schematic
CONTENTS
SECTION 1 . . . . SUMMARY
SECTION 2 . . . . CABINET & MAIN CHASSIS
SECTION 3 . . . . ELECTRICAL
SECTION 4 . . . . MECHANISM OF VCR PART
SECTION 5 . . . . MECHANISM OF DVD PART
SECTION 6 . . . . REPLACEMENT PARTS LIST
1-2
SECTION 1
SUMMARY
CONTENTS
PRODUCT SAFETY SERVICING GUIDELINES FOR VIDEO PRODUCTS ............. 1-3
SERVICING PRECAUTIONS .................................................................................................. 1-4
• General Servicing Precautions
• Insulation Checking Prodedure
• Electrostatically Sensitive Devices
SERVICE INFORMATION FOR EEPROM (DVD).............................................................. 1-5
SPECIFICATIONS ...................................................................................................................... 1-6
1-3
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 trans-ported 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.
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 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.
0.15uF
1500 OHM
10 WATT
Place this probe
on each exposed
metal part.
1-4
SERVICING PRECAUTIONS
CAUTION : Before servicing the VCR+DVD 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 publications, always follow the safety precautions.
Remembers Safety First:
General Servicing Precautions
1. Always unplug the VCR+DVD AC power cord from the AC
power source before:
(1) Removing or reinstalling any component, circuit board,
module, or any other assembly.
(2) Disconnection or reconnecting any internal electrical
plug or other electrical connection.
(3) Connecting a test substitute in parallel with an elec-
trolytic 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 VCR+DVD 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
whitch instruments covered by this service manual might
be equipped.
5. Do not apply AC power to this VCR+DVD and/or any of its
electrical assemblies unless all solid-state device heat
sinks are cerrectly installed.
6. Always connect test instrument ground lead to the
appropriate ground before connection 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 (Note 1) should be more than 1Mohm.
Note 1 : Accessible Conductive Parts including 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 grouned-tip soldering iron to solder or unsolder
ES devices.
4. Use only an anti-static solder removal device. Some
solder removal devices not classified a “anti-static” can
generate electrical charges sufficient to damage ES
devices.
5. Do not use freon-propelled chemicals. These can
generate electrical charge sufficient to damage ES
devices.
6. Do not remove a replacement ES device from its protec
tive 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. (Normally 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.)
1-5
SERVICE INFORMATION FOR EEPROM (DVD)
POWER ON
DVD LOGO Status (NO Disk status)
Remotecontrol
Pause key-->1-->4-->7-->2 in order.
Press number 0~9, Press charater
A~F (1~6 for a while)
Use arrow key (
F D G E
) to move
to approprite position and make
changes
Press pause key once
Change will be applied when power
OFF-->ON.
* OPTION
• NTSC model doesn’t have VCR option and use DVD option B~F as VCR option. (only DVD exist)
• PAL model has another separate VCR option. (Both VCR and DVD exist)
NAME HEX
OPT 1 55
OPT 2 53
OPT 3 00
OPT 4 45
OPT 5 12
OPT 6 05
OPT 7 64
OPT 8 00
OPT9 00
OPT A 00
OPT B C0
OPT C 40
OPT D 20
OPT E 00
OPT F 03
OPT G 3D
DETECT NEW EEPROM (OPTION EDIT SCREEN)
1-6
SPECIFICATIONS
• GENERAL
Power requirements AC 120V , 60 Hz
Power consumption 19W
Dimensions (approx.) 430 X 78.5 X 275 mm (16.9 X 3.1 X 10.8 inches) (w x h x d)
Mass (approx.) 8.8 lbs (4.0 kg)
Operating temperature 5˚C to 40˚C (41˚F to 104˚F)
Operating humidity 5 % to 90 %
Signal system NTSC
• INPUTS
ANTENNA IN 75 ohms (VHF/UHF/CATV)
VHS VIDEO IN (LINE1, 2) 1 Vp-p 75 ohms, sync negative, RCA jack x 2
VHS AUDIO IN (LINE1, 2) -6.0 dBm more than 47 kohms, RCA jack (L, R) x 2
• OUTPUTS
VIDEO OUT 1 Vp-p 75 ohms, sync negative
S-VIDEO OUT (Y) 1.0 V (p-p), 75 ohms, negative sync, Mini DIN 4-pin x 1
(C) 0.286 V (p-p) 75 ohms
COMPONENT VIDEO OUT (Y) 1.0 V (p-p), 75 ohms, negative sync, RCA jack x 1
(Progressive Scan) (Pb)/(Pr) 0.7 V (p-p), 75 ohms, RCA jack x 2
Audio output (digital audio) 0.5 V (p-p), 75 ohms, RCA jack x 1
Audio output (optical audio) 5 V (p-p), 75 Ω, Optical connector x 1
Audio output (analog audio) 2.0 Vrms (1 KHz, 0 dB), 330 ohms, RCA jack (L, R) x 1
RF OUT Channel 3 or 4 (Switchable)
• VCR Specifications
Head system Four head helical scan azimuth system
Timer 12-hour display type with AM, PM
Tape speed SP: 33.35 mm/sec, LP: 16.67 mm/sec, SLP: 11.12 mm/sec
Tape width 12.7 mm
Maximum recording time SP: 2 HOURS (T-120), SLP: 6 HOURS (T-120)/8 HOURS (T-160)
Rewind time About 3 minutes (T-120)
Antenna 75 ohms (VHF/UHF)
VHF output signal Channel 3 or 4 (Switchable)
Channel coverage VHF: 2-13, UHF: 14-69, CATV: 1-125 (4A, A-W, W+1 - W+84, A-5 A-1)
Frequency range 20Hz to 20kHz
Signal-to-noise ratio More than 43dB
Dynamic range More than 88 dB
Channel separation More than 60 dB
• DVD Specifications
Laser system Semiconductor laser, wavelength 650 nm
Frequency response DVD (PCM 96 kHz): 8 Hz to 44 kHz,
DVD (PCM 48 kHz): 8 Hz to 22 kHz
CD: 8 Hz to 20 kHz
Signal-to-noise ratio More than 100dB (ANALOG OUT jacks only)
Harmonic distortion Less than 0.008%
Dynamic range More than 95 dB (DVD/CD)
• Accessories:
Video cable x 1, Audio cable x 1, RF 75-ohm Coaxial Cable x 1, Remote control x 1, Batteries(AAA) x 2
2-1
SECTION 2
CABINET & MAIN CHASSIS
CONTENTS
EXPLODED VIEWS .....................................................................................................................2-2
1. Cabinet and Main Frame Section ...........................................................................................2-2
2. Packing Accessory Section ....................................................................................................2-3
2-2
EXPLODED VIEWS
1. Cabinet and Main Frame Section
280
A43
260
A44
A26
A00
250
300
462
467
467
457
467
A46
A47
468
468
468
323
265
467
465
330
452
452
261A
261A
261A
261A
285
274
283
284
286
A
5
4
3
2
1
BCD
2-3
2. Packing Accessory Section
BATTERY
808
BAG
804
PACKING, CASING
803
806
INSTRUCTION ASSEMBLY
CABLE(COAXIAL)
810
CABLE ASS'Y RF
801
REMOTE CONTROLLER
ASSEMBLY
900
BOX
802
PACKING, CASING
803
811
812
PLUG ASS'Y 1WAY
PLUG ASS'Y 2WAY
3-1
SECTION 3
ELECTRICAL
CONTENTS
OVERALL WIRING DIAGRAM.....................3-2
VCR PART
ELECTRICAL ADJUSTMENT
PROCEDURES ..................................................3-3
ELECTRICAL
TROUBLESHOOTING GUIDE
......................3-4
1. POWER(SMPS) CIRCUIT .............................3-4
2. SYSTEM/KEY CIRCUIT ................................3-7
3. SERVO CIRCUIT ...........................................3-8
4. OSD CIRCUIT ..............................................3-10
5. Y/C CIRCUIT ................................................3-11
6. HI-FI CIRCUIT..............................................3-15
7. TUNER/IF CIRCUIT .....................................3-18
BLOCK DIAGRAMS ......................................3-20
1. POWER (SMPS) BLOCK DIAGRAM ..........3-20
2. TU/IF BLOCK DIAGRAM ............................3-22
3. Y/C BLOCK DIAGRAM ...............................3-24
4. NORMAL AUDIO BLOCK DIAGRAM .........3-26
5. HI-FI BLOCK DIAGRAM .............................3-28
6. SYSTEM BLOCK DIAGRAM ......................3-30
CIRCUIT DIAGRAMS ....................................3-32
1. POWER (SMPS) CIRCUIT DIAGRAM ........3-32
2. TU/IF CIRCUIT DIAGRAM ..........................3-34
3. A/V CIRCUIT DIAGRAM .............................3-36
4. HI-FI CIRCUIT DIAGRAM ...........................3-38
5. JACK CIRCUIT DIAGRAM..........................3-40
6. SYSTEM CIRCUIT DIAGRAM.....................3-42
7. KEY CIRCUIT DIAGRAM ............................3-44
8. TIMER CIRCUIT DIAGRAM ........................3-46
• WAVEFORMS................................................3-48
• CIRCUIT VOLTAGE CHART.........................3-50
PRINTED CIRCUIT DIAGRAMS................3-52
1. MAIN P.C.BOARD .......................................3-52
2. MAIN P.C.BOARD .......................................3-54
3. POWER P.C.BOARD...................................3-56
DVD PART
ELECTRICAL TROUBLESHOOTING
GUIDE & WAVEFORMS
...............................3-58
1. SYSTEM OPERATION FLOW.....................3-58
2. TEST & DEBUG FLOW...............................3-59
DETAILS AND WAVEFORMS ON
SYSTEM TEST AND DEBUGGING
..........3-65
1. SYSTEM 27MHZ CLOCK,
RESET, FLASH R/W SIGNAL .....................3-65
2. SDRAM CLOCK ..........................................3-67
3. TRAY OPEN/CLOSE SIGNAL.....................3-67
4. SLED CONTROL RELATED SIGNAL
(NO DISC CONDITION)...............................3-69
5. LENS CONTROL RELATED SIGNAL
(NO DISC CONDITION)...............................3-69
6. LASER POWER CONTROL RELATED
SIGNAL(NO DISC CONDITION) .................3-70
7. DISC TYPE JUDGEMENT WAVEFORM ....3-70
8. FOCUS ON WAVEFORM ............................3-72
9. SPINDLE CONTROL WAVEFORM
(NO DISC CONDITION)...............................3-73
10. TRACKING CONTROL RELATED
SIGNAL(SYSTEM CHECKING) ................3-74
11. RF WAVEFORM.........................................3-75
12. MT1379 AUDIO OPTICAL AND
COAXIAL OUTPUT (ASPDIF)...................3-75
13. MT1379 VIDEO OUTPUT WAVEFORM....3-76
14. AUDIO OUTPUT FROM AUDIO DAC .......3-77
BLOCK DIAGRAMS ......................................3-79
1. OVERALL BLOCK DIAGRAM ....................3-79
2. SERVO BLOCK DIAGRAM.........................3-80
3. MPEG & MEMORY BLOCK DIAGRAM......3-81
4. VIDEO & AUDIO BLOCK DIAGRAM..........3-82
CIRCUIT DIAGRAMS ....................................3-83
1. SYSTEM CIRCUIT DIAGRAM.....................3-83
2. RF & DSP SERVO CIRCUIT DIAGRAM .....3-85
4. AV/JACK CIRCUIT DIAGRAM ....................3-87
• CIRCUIT VOLTAGE CHART.........................3-89
3-2
OVERALL WIRING DIAGRAM
PMC01
CFG
12VA(CAP)
5.2VA
CAP REV'H'
I-limit
MOTOR GND
GND
12VA(DRUM)
CAP CTL
LD IN
DFG/FG
DRUM CTL
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
P3D01
SP PB A
SP REC
SP PB B
EP PB B
EP REC
EP PBA
Hi-Fi PB A
Hi-Fi REC
Hi-Fi PB B
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
PPM01 PMP01
24VA
GND
14VA
GND
5.3VA
33VA
GND
4VA
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
PMD01 PMD02
Vcc(HF)
RF
DVD_LD
DVD_PD
VOL(DVD)
GND
VC_INPUT
Vcc(HF)
F
E
A
D
C
B
F(+)
T(-)
T(+)
F(-)
Vcc
GND
CD_LD
CD_PD
VOL(CD)
123456789
10111213141516171819202122
23
123456789
10111213141516171819202122
23
PMD03
SPM +
SPM -
FM +
FM -
LM -
LM +
SW(OPEN)
SW(CLOSE)
GND
SW(LEAD IN)
GND
123456789
10
11
123456789
10
11
P3D02
CTL(+)
CTL(-)
A/E(+)
A/E(-)
A.REC
A.PB
1
2
3
4
5
6
1
2
3
4
5
6
GND
FULL ERASE
P3D03
1
2
1
2
DECK MD
ONE
BOARD
SMPS
BOARD
ONE
BOARD
3-3
ELECTRICAL ADJUSTMENT PROCEDURES
1. Servo Adjustment
1) PG Adjustment
• Test Equipment
• Adjustment And Specification
a) OSCILLOSCOPE b) NTSC MODEL : NTSC SP TEST TAPE
MODE
PLAY
• Adjustment Procedure
a) Insert the SP Test Tape and play.
Note - Adjust the distance of X, pressing the Tracking(+) or Tracking(-) when the “ATR” is blink after the
SP Test Tape is inserted.
b) Connect the CH1 of the oscilloscope to the H/SW(TP) and CH2 to the Video Out for the VCR.
c) Trigger the mixed Combo Video Signal of CH2 to the CH1 H/SW(TP) and then check the distance (time
difference), which is from the selected A(B) Head point of the H/SW(TP) signal to the starting point of
the vertical synchronized signal, to 6.5H ± 0.5H (412µs, 1H=63µs).
• PG Adjustment Method
a-1) Payback the SP standard tape
b-2) Press the “OK(ENTER)” key on the Remote controller and the “REC” key on the Front Panel the same
time, then it goes in to Tracking initial mode.
c-3) Repeat the above step(No.b-2), then it finishes the PG adjusting automatically.
d-4) Stop the playback, then it goes out to PG adjusting mode after mony the PG data.
• CONNECTION
• WAVEFORM
V.Out
H/SW(TP)
R/C TRK JIG KEY 6.5 ± 0.5H
MEASUREMENT POINT ADJUSTMENT POINT SPECIFICATION
V.Out
H/SW
(TP)
OSCILLOSCOPE
CH1 CH2
V.outH/SW
R/C KEY
(TP)
H/SW
Composite
VIDEO
6.5H(412µs)
VCR PART
3-4
ELECTRICAL TROUBLESHOOTING GUIDE
NO
Check or Replace
the D102.
Replace the D111.
Replace the D110.
Replace the D113.
YES
YES
Is the D113 normal?
Power Line of Main
PCB is short.
1. Power(SMPS) CIRCUIT
NO 5.3VA.
Replace the F101.
(Use the same Fuse)
Is the F101 normal?
Is the R101
normal?
Is the BD101
normal?
NO
NO
NO
NO
NO
NO
NO
NO
NO
Replace the
BD101.
Replace the R101.
Is the D102
normal?
Replace the D118
(MTK)/D112(ST).
Replace the IC103.
YES
YES
YES
YES
YES
YES
YES
Is Vcc(9V~18V) supplied to IC101 Pin2?
Are the
D118 (MTK)
/D112(ST) normal?
Are the about 2.5V
at the IC103 Pin1?
Is the D111 normal?
Is the D110 normal?
(1) No 5.3VA (SYS/Hi-Fi/TUNER)
3-5
NO 33V.
Is the Vcc(33V) supplied to Q161 Emitter?
Check or Replace
the D113.
Is the Q162 Base
“H”?
Check the PWR CTL
“H” signal from µ-com
Check or Replace
the Q161
YES
YES
YES
(5) No 33V
NO 5V.
Check or Replace
the D118.
Is the Vcc(5.3V) supplied to Q160 Emitter?
Check or Replace
the Q160
Is the Q162 Base
“H”?
NO
NO
Check the PWR CTL
“H” signal from µ-com
YES
YES
YES
(2) No 5V
No 3.3V.
Check or Replace
the D111
Check the PWR CTL
“H” signal from µ-com
Is there about 3.7V
at the IC152 pin1?
Is there about 3.3V~
5V at the IC152 pin4?
Check the IC152
and Replace
NO
NO
YES
YES
YES
(3) No 3.3V
No SW5V
Check or Replace
the D118.
Is the Vcc(5.3V) supplied to Q163 Emitter?
Is the Q164 Base
“H”?
NO NO
Check the PWR CTL
“H” signal from µ-com
NO NO
YES
YES
Check or Replace
the Q163
YES
(4) No SW5V
3-6
NO 13VA.
Check or Replace
the D110.
Is the Vcc(13V)
supplied to C123?
Check or Replace
the cap/Drum
Is the D117/D115
Normal?
NO
NO
Replace the
D117/D115.
YES
YES
YES
(6) No 13V(TO Cap, Drum Motor)
NO 8V.
Is there about 13V
at the IC151 pn1?
YES
Is there about 3.3V~
5V at the IC151 pin4?
YES
Check the IC151
and Replace
YES
(7) No 8V
Check or Replace
the D110.
NO
NO
Check the PWR CTL
“H” signal from µ-com
NO 33V.
Is the Vcc(12V) supplied
to Q165 Collector?
Check or Replace
the D110.
Is the Vcc(10V) supplied to Q165 Base
Check or Replace
the ZD171.
Check or Replace
the Q165
YES
YES
YES
(9) No 9V
No REG 12V
Check or Replace
the D110.
Is the Vcc(13V) supplied
to Q156 Collector?
Is the Vcc(13V) supplied to Q156 Base
NO NO
Check the PWR CTL
“H” signal from µ-com
Check the 33V
Line
NO NO
YES
YES
Check or Replace
the Q156
YES
(8) No REG 12V
3-7
2. SYSTEM/KEY CIRCUIT
(1) AUTO STOP
(2) The unstable loading of a Cassette tape
Auto Stop
Does the SW30 waveform
appear at the IC501
Pin18?
Do the T-UP Reel Pulses
appear at the IC501 Pin80?
Is 12V applied to the
PMC01 Pin8?
Check the Drum Motor
signal.
Does 5V appear at the
RS501?
Check the Q160 Power
Circuit.
Refer to “SMPS DRUM
12 Volt Trouble Shooting”.
Is 5V applied to the
R531 ?
Refer to SMPS 5.3VA
troubleshooting.
Check the IC501
Pins22, 23, 24, 25.
Do T/UP Reel Pulses
appear at the point
between R556 and R536?
Replace the T/UP Reel
Sensor (RS501).
Check the CST SW and
the peripheral circuitry.
Replace the IC501.
The unstable loading of a
Cassette tape
Does the “H” signal appear
at the IC501 Pin60 during
inserting the CST ?
Does the “L” signal appear
at the IC501 Pin19 during
inserting the CST?
Check the Deck
Mechanism.
Caution :
Auto stop can occur because Grease or Oil is dried up
YES
YES
YES
NO
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO NO
YES
YES YES
3-8
3. SERVO CIRCUIT
(1) Unstable Video in PB MODE
Unstable Video in
PB Mode.
Does the Noise level of the
screen change
periodically?
Do the CTL pulses appear
at the IC501 Pin97?
Is adjusting the height of
the CTL Head accurate?
Readjust the height of the
CTL Head.
Replace the IC501.
Refer to “When the Y signal
doesn’t appear on the
screen in PB Mode”.
Does the CFG waveform
appear at the IC501
Pin87?
On tracking do the CTL
pulses move?
Does the Video Envelope
waveform appear at the
IC501 Pin9?
Replace the IC501.
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
(2) When the Drum Motor
(2) doesn’t run.
Do the DFG Pulses appear
at the PMC01 Pin11?
Replace the DRUM-M or
CAP-M.
Aren’t the foil patterns and
the Components between
IC501 Pin 90 and PMC01
Pin11 short?
Replace the IC501.
Refer to “(2)
No 12VA of Power section”
Do the Drum PWM Pulses
appear at the IC501
Pin76?
Aren’t the foil patterns and
the Components between
IC501 Pin76 and PMC01
Pin12 short?
Do the DFG Pulses appear
at the IC501 Pin90?
Do the Drum PWM Pulses
appear at the IC501
Pin76?
Aren’t the connecting patterns and the Components
between IC501 Pin76 and PMC01 Pin12 short?
When the Drum Motor
doesn’t run,
Does 12V appear at the
PMC01 Pin8?
Does 2.8V appear at the
PMC01 Pin12?
Check the connector
(PMC01) and the Drum
Motor Ass’y.
NO
YES
YES
YES
NO
NO
NO
NO
NO
YES
YES
YES
3-9
Does the CFG signal appear at the
PMC01 Pin1?
Does the PWM signal appear at the
IC501 Pin77?
Does 2.8V appear at the PMC01 Pin 9?
Check the PMC01 and the Capstan
Motor Ass’y.
Does the Capstan PWM signal appear at
the IC501 Pin77?
Aren’t the foil patterns and Components
between IC501 Pin77 and PMC01
Pin9 short?
Does the CFG signal come into the
IC501 Pin87?
Aren’t the foil patterns and Components
between IC501 Pin77 and PMC01
Pin9 short?
2. SERVO CIRCUIT
(3) When the Capstan Motor doesn’t run,
NO
NO
NO
YES
YES
YES
When the Capstan Motor doesn’t run,
Does 12VA appear at the PMC01?
YES
Replace the IC501.
YES
NO
NO
YES
Refer to “SMPS(CAPSTAN/12Volt)
Trouble Shooting”.
Aren’t the foil patterns and component
between IC501 Pin87 and PMC01
Pin1 short?
Check the Capstan Motor Ass’y.
NO
3-10
4. OSD CIRCUIT
(1) No OSD display.
(2) I
2
C BUS CHECK
KEY doesn’t working.
Is 5V applied to the IC501
Pin99?
Does LED or FLD change
when a function button is
pressed?
No OSD or F.OSD display.
Is 5.3V applied to the
IC501 Pin53?
Does oscillation occur at
the IC501 Pins44, 45?
Replace the IC501.
The I2C waves don’t
come out.
Does Power appear at the
Pull up impedence
(R569, R507)?
Replace the IC501.
Refer to “SMPS 5.3VA
Trouble Shooting”.
Replace the defective
switches.
Refer to “SMPS 5.3VA
Trouble Shooting”.
Check or Replace the pheripheral Circurity.(L511,
R518, C596, C595)
Refer to “SMPS 5.3VA
Trouble Shooting”.
YES
YES
YES
YES
NO
NO
NO
NO
NO
2. SERVO CIRCUIT
(4) KEY doesn’t working
3-11
5. Y/C CIRCUIT
(1) No Video in EE Mode,
No Video in EE Mode
Check the Tuner Pin16V
Check the SW 5V, 5.3VA
Line.(Power Circuit)
Is I2C BUS signal applied
to the IC301 Pins73, 74?
Does the Video signal
appear at the IC301
Pin15?
Is 5.0V applied to the
IC301Pins4, 22, 47, 60, 84?
Does the Video signal
appear at the IC301
Pin29?
Does the Video signal
appear at the IC501
Pin52?
Does the Video signal
appear at the IC602
Pin7?
Check the path of the signal between the IC301 Pin
29 and IC501 Pins50.
Is there Vcc 5V on the
IC602 Pin6
Does the Video signal appear at
the IC602 Pin1(DVD MODE)
Replace the IC602.
Check the 5V.
(Power Circuit)
Check the C327.(AGC)
Check the System Circuit.
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
3-12
3. Y/C CIRCUIT
(2) When the Y(Luminance) signal doesn’t appear on the screen in PB Mode,
Is 5.2VT, 5.3VA applied to the
IC301 Pins22, 47, 60, 84?
Is the Y/C Bus siganl
applied to the IC301
Pins73, 74?
Does the normal RF signal
appear at the IC301 Pin 6?
Check the SW 5V Line.
(Power Circuit)
Check the System Circuit.
(IC501 Pin18)
Check the V.H.S/W level.
(Check R328)
Check the IC301
Refer to ‘SYSTEM I2C BUS
CHECK Trouble Shooting’.
Is the V.H.S/W signal
applied to the IC301 Pin70?
Is V.H.S/W “H” about 3.4V
at the IC301 Pin 80?
Clean the Drum.
Check the path of the
Y(Luminance) RF signal.
(C337, C340)
Does the Y(Luminance)
signal appear at the IC301
Pin9?
Is the Y(Luminance) Video
waveform showed up at the
IC301 Pin43?
Replace the IC301.
NO
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
3-13
3. Y/C CIRCUIT
(3) When the C(Color) signal doesn’t appear on the screen in PB Mode,
Is 5.2VT/5.3VA applied to the
IC301 Pins 22, 47, 60, 84.
Is the Color signal applied
to the IC301 Pin 57?
Check the SW 5V, 5.3V
Line. (Power Circuit)
Replace the X301.
Check the Color Pass.
Is normal the X301
(3.58MHZ) of oscillation
Frequency?
Replace the IC301.
Does the Color signal
appear at the IC301 Pin55?
Replace the IC301.
NO
YES
YES
YES
NO
NO
NO
3-14
3. Y/C CIRCUIT
(4) When the Video signal doesn’t appear on the screen in REC Mode,
Is the EE signal normal?
Is 5.2V/5.3VA applied to the
IC301 Pins 4, 22, 47, 60, 84?
Does the REC RF signal
appear at the IC301
Pin76?
Check EE Mode.
Check the system of
REC”H”(IC501 pin74)
Replace the IC301.
Check the SW 5V/ 5.3VA
Line.(Power Circuit)
Check PB Mode.
Does the REC “H”(4V~5V)
signal appear at the Q303,
Q307 Base?
Check the REC Luminance
Pass and Color Pass.
Does PB Mdoe operate
normally?
YES
YES
YES
Does the REC RF signal
appear at the IC301
Pins86, 90?
Check the Drum &
Drum Connector.
YES YES
YES
NO
NO
NO
NO
NO
NO
3-15
6. Hi-Fi CIRCUIT
(1) No Sound(EE Mode)
YES
No Sound.
Check the SIF.IN of IC801 Pins57.
Check the DVD Audio of IC801
Pins12, 74.
Check the AV1 Audio of IC801
Pins11, 73.
Check the AV2 Audio of IC801
Pins9, 71.
Check the Vcc of IC801 Pins3, 5, 15,
32, 36, 46, 54.
YES
Check the IIC Clock and DATA at
IC801 Pins37, 38.
YES
Check the Audio of IC801 Pins78, 80.
YES
Check the Audio of C804, C854.
YES
Check the JK601.
Check the TU701 SIF Pin13.
NO
Check the DVD MODULE.
(PMD02 Pins13, 15).
NO
Check the Rear Jack.
(JK601 Audio in).
NO
Check the front Jack.
Timer (JK602, JK603).
NO
Check the Power 5.2V, 5.3VA, REG 9V.
Q701, PMP01 Pins1, 2, 5, 6.
YES
NO
Check the IC501 Pins71, 72.
NO
Replace IC801.
Replace C804, C854.
NO
NO
3-16
3. Y/C CIRCUIT
(2) Hi-Fi Playback
YES
YES
YES
YES
PB mode
No Sound.
Check the Vcc of IC801
(Pins3, 5, 15, 32, 36, 46, 54).
Check the Hi-Fi Selection switch.
(IC801 Pin39) and the Tape quality.
Is the RF Envelope at
IC801 Pin23 over 3Vp-p?
YES
Check IC801 Pin37(Data),
Pin38(Clock)
YES
Do Audio Signals appear at
IC801 Pin80(L-CH), 78(R-CH)?
YES
Do Audio Signals appear at
JK601?
Check Power.
NO
Check IC501 Pin19
(A.H/SW)
NO
NO
Check the parts of µ-COM
(IC501 Pins71, 72)
NO
Check the Connection at
P3D01 Pins7, 9.
NO
Check the Jack(JK801)
NO
Check C801, C851, R801,
R851.
YES
3-17
(3) Hi-Fi REC
Hi-Fi REC.
It is impossible to record Hi-Fi Audio
signal.
Check Vcc of IC801.
(Pins3, 5, 15, 32, 36, 46, 54)
YES
YES
Check IC801 Pin37(Data), Pin38(CLOCK).
YES
Do Audio signals appear at IC801 Pin6?
YES
Do Audio signals appear at IC301
Pin76(Normal Audio)?
YES
Do OSC signals appear at P3D02 pins4,5
(50Vp-p)
YES
YES
Check Power.
NO
Check ports of µ-CPM.
(IC501 Pins71, 72)
Check Audio input signal of IC801
Pin57(TU.A.), 7, 69(DVD.A.),
11, 73(AVI.A.), 9, 71(AV2.A.)
NO
Check C825, C306, R311, R312, R346.
Check REC OSC BLOCK
(FL301, Q301~Q305, Q308, Q309)
Is “High” IC501 Pin74 in REC mode.
NO
NO
NO
3-18
7. Tuner/IF CIRCUIT
(1) No Picture on the TV screen
No picture on the TV
screen
Does the Video signal at
the TU701 Pin16.
YES
YES
YES
Is +33V applied to TU701
Pin14?
YES
Is +5V applied to TU701
Pin3?
NO
Does the Video signal at
the IC501 Pin 52.
NO
Does the Video signal at
the IC609 Pin 23.
YES
NO
Check the signal flow from IC609
Pin23 to JK901 Pin Video out.
YES
Check 33V line.
NO
Check 5V line.
NO
YES
Does the Clock signal
appear at TU701 Pin9?
Check the lIC Clock Signal
of µ-COM Pin71.
NO
YES
Does the data signal
appear at TU701 Pin10?
Replace Tuner.
Check the signal from IC301
Pin29 to IC501 Pin50.
Check the signal from IC501
Pin52 to IC609 Pin4.
Check the lIC Data Signal
of µ-COM Pin72.
NO
3-19
(2) No Sound
No Sound.
Check the Vcc of TU701 Pins3, 14.
YES
Check 5.2V, 33V Line.
NO
Check the Tuner SiF signal at IC801
Pin57.
YES
Check the Audio of IC801 Pins78, 80.
YES
Check the Signal flow from IC801 Pins78,
80 to JK901 Audio out(L), (R)
YES
Check the Tuner SIF of TU701 Pin13.
NO
1. Check the Vcc(5.3VA, 9V) of IC801
Pins3, 5, 36, 54.
2. Check the IIC Clock and Data at IC801
Pins37, 38.
NO
3-20 3-21
BLOCK DIAGRAMS
1. POWER(SMPS) BLOCK DIAGRAM
BD101
T101
TRANS
R101
+
BR BL
(BK)(WH)
C103
!
!
!
!
!
!
FUSE
(F101)
NOISE FILTER
BLOCK
(C101,L102,
C102)
PHOTO COUPLER
(IC102)
ERROR
AMP
(IC103)
SNUBBER
BLOCK
(D101,C105
C106,R104)
DRIVE & S/W BLOCK
(IC101, D102, R105,
C104, C109 , C135)
Y-CAP
C111
Y-CAP
C110
FEED-BACK
BLOCK
R112,R113,
C133,R114.
R115,R116
R117)
RECTIFIER &
SMOOTING BLOCK
(D110,C123,C163,
R133,L122,C126)
RECTIFIER &
SMOOTING BLOCK
(D118,D112,C129,
C131,L124,L125)
RECTIFIER &
SMOOTING BLOCK
(D111,C127,L123,
C128)
RECTIFIER &
SMOOTING BLOCK
(D113,C132,R119)
CAP VCC
D115
D117
DRUM VCC
12V
8V
5.3VA
5V
3.3V
33V
12V REG BLOCK
(Q156,ZD103,C151,
R150,R153,C152)
8V REG BLOCK
(D114,IC151,R170,
C154,C159)
5V S/W BLOCK
(Q160,C155,D121,
R157,R158,R159,R160)
3.3V REG BLOCK
(IC152,C153,R156)
33V S/W BLOCK
(Q161,R154,R155,
R177)
5V S/W BLOCK
(Q163,C162,R173,
Q164)
PWR CTL'H'
SW5V
9V
9V REG BLOCK
(Q165,ZD171,C171,
R174,R175,R176)
PWR CTL BLOCK
(Q162,C161,R164,
R163)
657 8
2
31
COMBI NTSC
3-22 3-23
2. TU/IF BLOCK DIAGRAM
A.IN
CH S/W
REG 5V
CONTROL
V.IN
RF AGC
NC
ENABLE
CLOCK
DATA
AFT
A.OUT
SIF
TU 30V
NC
V.OUT
999 GND
100AFT
732TU.V.OUT
875 MOD A.IN
61 MOD CTL
107 5V
26 VCR 'H'
971 MOD VEDIO
71 IIC CLK
72 IIC DATA
781 SIF OUT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
COMBI NTSC
15833V
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