Toshiba SD-V290 User manual

SERVICE MANUAL
DVD VIDEO PLAYER &
VIDEO CASSETTE RECORDER
FILE NO. 810-200226
JANUARY, 2003
SD-V290
SD-V390

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 ............................................................................................................................................................3-13
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
• WAVEFORMS ..............................................................................................................................................................3-46
• CIRCUIT VOLTAGE CHART .......................................................................................................................................3-48
PRINTED CIRCUIT DIAGRAMS..............................................................................................................................3-50
1. MAIN P.C.BOARD......................................................................................................................................................3-50
2. KEY 1(LEFT) P.C.BOARD .........................................................................................................................................3-52
3. KEY 2(RIGHT) P.C.BOARD .......................................................................................................................................3-52
4. POWER P.C.BOARD .................................................................................................................................................3-53
DVD PART
ELECTRICAL TROUBLESHOOTING GUIDE ....................................................................................................3-54
1. µ-COM CIRCUIT ........................................................................................................................................................3-54
2. MPEG CIRCUIT .........................................................................................................................................................3-56
3. RF/Servo CIRCUIT ....................................................................................................................................................3-57
BLOCK DIAGRAMS.....................................................................................................................................................3-61
1. DVD Overall BLOCK DIAGRAM...............................................................................................................................3-61
2. RF/CD DSP/DVD DSP/DVD SERVO BLOCK DIAGRAM.........................................................................................3-62
3. Audio BLOCK DIAGRAM..........................................................................................................................................3-63
4. MEMORY BLOCK DIAGRAM....................................................................................................................................3-64
5. µ-COM BLOCK DIAGRAM ........................................................................................................................................3-65
CIRCUIT DIAGRAMS ..................................................................................................................................................3-66
1. DVD DSP CIRCUIT DIAGRAM..................................................................................................................................3-66
2. DRIVE & RF CIRCUIT DIAGRAM .............................................................................................................................3-68
3. MEMORY CIRCUIT DIAGRAM..................................................................................................................................3-70
4. INTERFACE CIRCUIT DIAGRAM .............................................................................................................................3-72
5. µ-COM/Expander CIRCUIT DIAGRAM.....................................................................................................................3-74
6. Jack CIRCUIT DIAGRAM..........................................................................................................................................3-76
• WAVEFORMS ..............................................................................................................................................................3-78
• CIRCUIT VOLTAGE CHART .......................................................................................................................................3-80
PRINTED CIRCUIT DIAGRAMS..............................................................................................................................3-86
1. MAIN P.C.BOARD (TOP VIEW).................................................................................................................................3-86
1. MAIN P.C.BOARD (BOTTOM VIEW) ........................................................................................................................3-88

OVERALL WIRING DIAGRAM
3-2
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
PMP01
5.3VA
5.0V
GND
CAP Vcc
REG 12V
33V
12VA(DRUM)
PWR CTL 'H'
GND
NC
GND
GND
FD(-)
FD(+)
-27VA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
5.3VA
8V
GND(M)
REG 12V
3.3V
5V
3.3V
GND GND
PDP01PPD01
1 2 3 4 5 6 7 8 9
1 2 3 4 5 6 7 8 9
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)
1 2 3 4 5 6 7 8 9
10
11
12 13 14 15 16 17 18 19 20 21 22 23
1 2 3 4 5 6 7 8 9
10
11
12 13 14 15 16 17 18 19 20 21 22 23
PM601
GND
DISPLAY CLK
DISPLAY ENA
DISPLAY DATA
REMOCON
KEY RETURN 1 KEY RETURN 2
5.3VA
FD(-)
FD(+)
-27VA
GND
1 2 3 4 5 6 7 8 9
10
11
12
1 2 3 4 5 6 7 8 9
10
11
12
PM603
VIDEO IN
GND
AUDIO 'L'
GND
AUDIO 'R'
5 4 3 2 1
5 4 3 2 1
PMD03
SPM +
SPM -
FM +
FM -
LM -
LM +
SW(OPEN)
SW(CLOSE)
GND
SW(LEAD IN)
GND
1 2 3 4 5 6 7 8 9
10
11
1 2 3 4 5 6 7 8 9
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
S/COMPO SW
COAXIAL
OPTICAL
GND
GND
K.RTN 2
DVD RESET
DVD ENA
DVD CLK
DVD DATA IN
DVD DATA OUT
GND
PVD02PMD01
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
Y
GND
Pb/C
GND
Pr
GND
C_V_OUT(DVD)
GND
D_A_L_OUT
GND
D_A_R_OUT
GND
A_MUTE_L
A_MUTE_R
GND
PDV03PMD02
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
GND
GND
DVD LED
VCR LED
5.3VA
K-RTN 1
K-RTN 2
GND
PM602PM603
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
DECK MD
MPEG
BOARD
SMPS
BOARD
TIMER
BOARD
KEY BOARD
VCR

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(W861, W862) and CH2 to the Video Out for the VCR.
c) Trigger the mixed Combo Video Signal of CH2 to the CH1 H/SW(W861, W862), and then check the dis-
tance (time difference), which is from the selected A(B) Head point of the H/SW(W861, W862) 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(W861, W862) R/C TRK JIG KEY 6.5 ± 0.5H
MEASUREMENT POINT ADJUSTMENT POINT SPECIFICATION
V.Out
H/SW(W861, W862)
OSCILLOSCOPE
CH1 CH2
V.outH/SW
R/C KEY
(W861, W862)
H/SW
Composite
VIDEO
6.5H(412µs)
VCR PART

3-4
ELECTRICAL TROUBLESHOOTING GUIDE
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
Replace the
BD101.
Replace the R101.
Is the D102
normal?
Check or Replace
the D102.
Replace the D112.
Replace the IC103.
YES
YES
YES
YES
YES
YES
YES
Is Vcc(8.5~21V) sup-
plied to IC101 Pin7?
NO
Is the D112 normal?
Is there about 2.5V
at the IC103 Vref?
Check the Main PCB
5.3VA/5.0V Line short?
(1) No 5.3VA (SYS/Hi-Fi/TUNER)
NO 12VA.
Check or Replace
the D110.
Is the Vcc(13V) supplied
to (+) terminal in D115?
Check or Replace
the Motor Vcc.
Is the Vcc(12V) supplied
to (-) terminal in D115?
NO
NO Replace the D115.
YES
YES
YES
(2) No 12VA (TO CAP, DRUM MOTOR)
NO 5.2VA.
5.3VA Line Check.
Is 5.3VA put into
the Q160 Emitter?
Is about 5V put into
the Q160 Base?
Is the Q162 Base
“H”?
NO
NO Check the Power
Control.
NO
Check or Replace the Q162,
R157, R158, R159, D121.
YES
YES
YES
Check or Replace
the Q162/Q160.
YES
(3) No 5.2V (SYS/Hi-Fi/TUNER)

NO -27VA.
Check or Replace
D108.
YES
(7) No -27VA
3-5
NO 5V.
5.3VA Line Check.
Is 5.3VA put into
the Q160 Emitter?
Is about 5V put into
the Q160 Base?
Is the Q162 Base
“H”?
NO
NO
NO
Check the Power
Control.
Check or Replace the Q162,
R157, R158, R159, D121.
YES
YES
YES
YES
Check or Replace
the Q162/Q160
(4) No 5V (TO DVD)
No 33V.
Check the Power
Control.
Is Q162 Base “H”?
Check or Replace
Q161, R154, R155.
NO
YES
YES
(5) No 33V (TUNER)
No REG 12V.
Check or Replace
D110.
Is 13V put into the
Q156 Collector?
Is 13V put into the
R153 Base?
NO
Check 33V Line.
NO
YES
YES
Check or Replace the Q156,
ZD103, R153, C151.
YES
(6) No REG 12V

3-6
NO 8V.
Check or Replace
the D110.
Is Vcc(13V) supplied to
(+) terminal in D114?
Is the Q162 Base
“H”?
Is Vcc(12V) supplied
to IC151 Pin1?
NO
NO Check or Replace
the D114.
NO Check the Power
Control.
YES
YES
YES
Check or Replace
IC151, R170, C154.
YES
(8) No 8V(TO DVD)
NO 3.3V.
Is Vcc(4V) supplied
to IC152 Pin1?
YES
Is the Q162 Base
“H”?
YES
Check or Replace
IC152, R156, C153.
YES
(9) No 3.3V(TO DVD)
Check or Replace
the D111.
NO
NO Check the Power
Control.

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 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?
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) I2C BUS CHECK
KEY doesn’t working.
Is 5V applied to the IC501
Pin79?
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 phe-
ripheral 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
Does the Video signal
appear at the IC302
Pins1, 5?
Is there 5V at the IC302
Pin6?
Replace the IC302.
Does the Video signal
appear at the IC301
Pins28, 30, 32?
Is REG 5.0V applied to the
IC301Pins23, 44, 45, 52, 68,
77?
Does the Video signal
appear at the IC301 Pin26?
Does the Video signal
appear at the IC501 Pin52?
Does the Video signal
appear at the IC602 Pin7?
Check the REG 5V Line.
(Power Circuit)
Is I2C BUS signal applied to
the IC301 Pins53, 54, 55?
Replace the IC301.
Check the path of the sig-
nal between the IC301 Pin
26 and IC501 Pins50, 52.
Is there 5V on the plus
terminal of the C614?
Check the REG 5V Line.
(Power Circuit)
Replace the IC602.
Check the System Circuit.
(Refer to ‘SYSTEM I2C BUS
CHECK Trouble Shooting’)
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
YES
YES
Check DVD Video Input
(IC802, Pin29), Tuner
Video Input (TU701 Pin24),
Line Video Input (JK801),
respectively.
NO

3-12
3. Y/C CIRCUIT
(2) When the Y(Luminance) signal doesn’t appear on the screen in PB Mode,
Is 5V applied to the IC301
Pins23, 44, 45, 52, 68, 77?
Is the Y/C Bus siganl
applied to the IC301
Pins53, 54, 55?
Does the normal RF signal
appear at the IC301 Pin 14?
Check the line of the REG
5V Line. (Power Circuit)
Check the System Circuit.
(IC501 Pin18)
Check the V.H.S/W level.
Refer to ‘SYSTEM Y/C
BUS CHECK Trouble
Shooting’.
Is the V.H.S/W signal
applied to the IC301 Pin57?
Does the Rectangular
waveform(5V) appear at
the IC301 Pin57(V.H.S/W)
Clean the Drum.
Check the C324.
Check the R328, C322,
C323.
Does the Y(Luminance)
signal appear at the IC301
Pin20?
Is the Y(Luminance) Video
waveform showed up at the
IC301 Pin22?
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 5V applied to the IC301
Pins23, 44, 45, 52, 68, 77?
Does the Color signal
appear at the IC301
Pins41, 50?
Check the line of the REG
5V Line. (Power Circuit)
Replace the X301.
Check the C342, C341,
R333.
Is normal the X301
(3.58MHZ) of oscillation
Frequency?
Replace the IC301.
Does the Color signal
appear at the IC301 Pin48?
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,
YES
YES
YES
YES
YES
YES
NO
NO
YES
YES
YES
YES
YES
Check system part
(V.H/SW)
Replace the IC301.
Check the drum
*OPTION
Pins72, 73, 74(SP)
Pins65, 66, 67(EP)
REC mode
Check the EE mode
NO
Is EE mode normal?
Is color normal? A
A
YES YES
Is brightness normal?
Does signal appear at
IC301 Pins41, 50?
NO Check X301 oscillation
frequency.
YES
Is the brightness signal sup-
plied to IC301 Pins18?
Is 5V supplied to IC301
Pins23, 44, 45, 68, 77?
Check the power of Pins23,
44, 45, 52, 68, 77.
Check the 5V power
NO
NO
NO
NO
NO
Is Y/C Bus applied to
IC301 Pins53, 54, 55?
Check the REG 5V power Check system part
Do X301 and X-TAL
oscillate? Check X301, 302
Is V.H SW supplied to
IC301 Pin57?
Does the FM signal appear
at IC301 Pins73(SP)/
66(EP)?

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 Pins9, 11).
NO
Check the Rear Jack.
(JK601 Audio in).
NO
Check the front Jack.
(JK5L1 Audio in).
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
appear at IC302 Pin7.
NO
Does the Video signal at
the IC501 Pin 52.
YES
NO
Does the Video signal at
the IC602 Pin 7.
YES
NO
Check the signal flow from IC602
Pin7 to JK601 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 flow from
IC501 Pin27.(Pin27 is ‘L’
state in Tuner Mode)
Check the signal from IC301
Pin26 to IC501 Pin50.
Check the signal from IC501 Pin52 to IC602 Pin1 and IC602 Pin2.
(IC602 Pin2 is ‘L’state in VHS mode)
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 JK601 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