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ELECTRICAL TROUBLESHOOTING GUIDE
1. Power Circuit(SMPS)
(1) No 5.3VA.
No 5.3VA.
YES
NO Replace the F101
Is the F101 normal?
(Use the same Fuse).
YES
NO
Is the BD01 normal? Replace the BD101.
YES
NO
Is the R101 normal? Replace the R101.
YES
Does the oscillation waveform appear at NO Is Vcc(about 15~19V) permittable at the
the IC101 Pin 1? IC101 Pin 4?
YES NO
Check or Replace the D103.
NO
Is there DC voltage at the IC101 Pin 4? Replace the IC102.
YES
NO
Is there about 2.5V at the IC103 Vref ? Replace the IC103.
YES
NO
Is the D106 normal? Replace the D106.
YES
Check the Main PCB 5.3VA/5.0V
Line short?
3-2
7. Power Circuit(SMPS)
(2) No 13VA.
No 13VA.
YES
NO
Does 5.3VA work normally? Check whether 5.3VA is out of order.
YES
NO
Is the D109 normal? Replace the D109.
YES
Check 13VA/12VA Line of the
Main PCB short.
(3) No 12VA.
No 12VA.
YES
NO
Does 13VA work normally? Check whether 13VA is out of order.
YES
NO
Is the D151, D153 normal? Replace the D151, 153.
YES
Check or Replace the Motor Vcc.
3-3
7. Power Circuit(SMPS)
(4) No 5V.
No 5V.
YES
Is 5.3VA put into the Q153/Q155
collector?
YES
NO
Is the Q156 Base "H"? Check the Power Control.
YES
Is about 5.5V put into the NO
Does the 13VA Line work normally?
Q153/Q155 Base?
YES NO
1 Check the 13VA Line.
Check or Replace the Q153/Q155.
2 Check the Peripheral
2 Circuitry of ZD153.
3-4
2. SERVO CIRCUIT
(1) Unstable Video in PB MODE
Unstable Video in
PB Mode.
YES
Does the Noise level of the
screen change
periodically?
YES
Do the CTL pulses appear NO Is adjusting the height of
at the IC501 Pin 89? the CTL Head accurate?
NO
YES
Does the CFG waveform Readjust the height of the
appear at the IC501 CTL Head.
Pin 93?
YES
On tracking do the CTL NO
Replace the IC501.
pulses move?
YES
Does the Video Envelope NO Refer to "When the Y signal
waveform appear at the doesn't appear on the
IC501 Pin 82? screen in PB Mode".
YES
Check Power. Refer to "(3)
Replace the IC501.
No 12VA of Power section"
(2) When the Drum Motor Do the Drum PWM Pulses NO
(2) doesn't run. Do the DFG Pulses appear
appear at the IC501
at the IC502 Pin 8?
Pin 9? YES
When the Drum Motor YES NO
doesn't run,
Aren't the foil patterns and
Check the IC502 and
the Components between
the Drum Motor Ass'y.
IC501 Pin 9 and PMD01
Does 12VA appear at the Pin 1, 2 short?
IC502 Pin 21? NO
Aren't the foil patterns and
Do the DFG Pulses appear
NO the Components between
Does PG+, PG- appear at at the IC501 Pin 97?
IC501 Pin 97 and IC502
the PMD01 Pin 1, 2? NO Pin 8 short?
Do the Drum PWM Pulses NO
Check the connector appear at the IC501 Replace the IC501.
(PMD01) and the Drum Pin 9?
Motor Ass'y.
Aren't the connecting patterns and the Components
between IC501 Pin 9 and PMD01 Pin 1, 2 short?
3-5
2. SERVO CIRCUIT
(3) When the Capstan Motor doesn't run,
When the Capstan Motor doesn't run,
NO Refer to "SMPS(CAPSTAN/12Volt)
Does 12VA appear at the PMC01?
Trouble Shooting".
YES
Does 2.8V appear at the PMC01 Pin 4?
NO
YES
Check the PMC01 and the Capstan Does the PWM signal appear at the
Motor Ass'y. IC501 Pin 10?
YES
NO
Aren't the foil patterns and Components Does the CFG signal appear at the
between IC501 Pin 10 and PMD01
Pin 4 short? PMC01 Pin 6?
YES
NO
Does the CFG signal come into the
Check the Capstan Motor Ass'y.
IC501 Pin 93?
NO
YES
Aren't the foil patterns and component
Does the Capstan PWM signal appear at
between IC501 Pin 93 and PMC01
the IC501 Pin 10?
Pin 6 short?
NO
YES
Aren't the foil patterns and Components
between IC501 Pin 10 and PMC01 Replace the IC501.
Pin 4 short?
3-6
3. Y/C CIRCUIT
(1) No Video in EE Mode,
No Video in EE Mode
NO Check the Video Input
Does the Video signal
Jack.
appear at the IC301 Pin 31?
(Line In Jack)
YES
Is 5V applied to the IC301 NO Check the 5V Line.
Pins 12, 36, 61, 67, 90, 96? (Power Circuit)
YES
NO NO Check the System Circuit.
Does the Video signal Is I2C BUS signal applied to
(Refer to `SYSTEM I2C BUS
appear at the IC301 Pin 52? the IC301 Pins 62, 63?
CHECK Trouble Shooting')
YES YES
Check C330. (AGC)
YES
Does the Video signal NO NO
Is there 13VA on the plus
appear at the Emitter Replace the IC301.
terminal of the C3M5?
terminal of the Q3M1?
Check the 13VA Line.
Replace the Q3M1. (Power Circuit)
3-7
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 NO Check the line of the 5.3V
Pins 12, 36, 61, 67, 90, 96? Line. (Power Circuit)
YES
Is the I2C Bus siganl applied NO Refer to `SYSTEM I2C BUS
to the IC301 Pins 62, 63? CHECK Trouble Shooting'.
YES
Does the normal RF signal NO Is the V.H.S/W signal NO Check the System Circuit.
appear at the IC301 Pin 79? applied to the IC301 Pin81? (IC501 Pin 24)
YES
Is V.H.S/W "H" about 4.5V NO
Check the V.H.S/W level.
at the IC301 Pin 81?
YES
YES
NO
Clean the Drum. Replace the IC301.
Does the Y(Luminance) RF NO YES
Check the path of the
signal appear at the IC301
Y(Luminance) RF signal.
Pin 18?
YES
Is the Y(Luminance) Video NO YES
Check the path of the
waveform showed up at the
Y(Luminance) RF signal.
IC301 Pin 39?
YES
Replace the IC301.
3-8
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 NO Check the line of the 5.3V
Pins 12, 36, 61, 67, 90, 96? Line. (Power Circuit)
YES
Does the Color signal NO NO
Does the X301(4.43MHZ) Replace the X301 or
appear at the IC301
or X302(3.58MHZ) oscillate? the X302.
Pin 71, 75 ?
Does the Color signal NO Check the Color Pass.
YES appear at the IC301 Pin55? (Check the C341)
Check the circuit of the YES
Replace the IC301. Replace the IC301.
IC301 Pins 60, 58, 35.
3-9
3. Y/C CIRCUIT
(4) When the Video signal doesn't appear on the screen in REC Mode,
NO
Is the EE signal normal? Check EE Mode.
YES
Is 5V applied to the IC301 NO Check the line of the 5.3V
Pins 12, 36, 61, 67, 90, 96? Line.(Power Circuit)
YES
Does PB Mdoe operate NO
Check PB Mode.
normally?
YES
NO Is the REC `H' signal NO Check the System of REC
Does the RF signal appear
(about 4V) applied to the `H'. (Q303 Base/IC501
at the IC301 Pin 87?
Q303 Base? Pin 55)
YES
Check REC Luminance YES
YES Replace the IC301.
Pass & Color Pass.
Does the REC RF signal NO Check the circuit of the YES
appear at the IC301
Pins 87, 88 ? IC301 Pins 86, 87, 88, 89.
YES
Check the Drum &
Drum Connector
3-10
4. AUDIO CIRCUIT
(1) No sound in EE Mode
No sound in EE Mode.
YES
No sound.
YES
NO Check the line of the 5V Line.
Is 5V applied to the IC301 Pin 96?
(Power Circuit)
YES
Is the Audio signal applied to the NO
Check the path of LINE/AUDIO.
IC301 Pin 9?
YES NO
Does the Audio signal appear at the Is the Audio Mute "High" signal applied
IC301 Pin 11? NO to the IC301 Pin 99?
YES YES
Check the connection of the Audio Check the IC501 Pin 51.
out Jack. (Audio Mute "H".)
Does the CLK/Data signal(I2C) Check the IC501 Pin 27(CLK),
appear at the IC301 Pins 62, 63 ? NO 28(Data) Line.
YES
Replace the IC301.
(2) No sound in PB MODE
No sound in PB Mode.
No sound.
YES
NO Check the circuit line of the 5V Line.
Is 5V applied to the IC301 Pin 96?
(Power Circuit)
YES
Does the CLK/Data signal(I2C) appear at NO Check the IC501 Pin 27 (CLK),
the IC301 Pins 62, 63? 28 (Data) Line.
YES
Does the Audio signal appear at the NO Check the connecting state between the
IC301 Pin 1? P3D02 Pin 6 and A/C Head.
YES YES
Does the Audio signal appear at the Is the Audio Mute "H" applied to the
IC301 Pin 11? IC301 Pin 99?
NO NO
YES
Replace the IC301. Check the IC501 Pin 55.
3-11
3. Y/C CIRCUIT
(3) No sound in REC Mode,
No sound in REC Mode,
YES
Sound is not recorded.
YES
NO Refer to "No sound in PB
Is Playback O.K.?
Mode,".
YES
Is the Audio signal applied NO Check the path of Line
to the IC301 Pin 9? Audio.
YES
Does the Audio waveform NO Is the "High" signal applied NO Check the CLK/Date line
appear at the IC301 Pin 4 ? to the IC301 Pin 99? and replace the IC301
YES YES
Is 5V applied to the FL301 Check the IC501 Pin 55
Pin 5 ? (Audio Mute "H").
NO
YES
Is 3.0~4.5V applied to the Check the line of the 5V
Collector of the Q301 ? Power Circuit.
NO
YES
Does the Erase signal Check the Audio R/P/E
appear at the FL301 Pin 2? connector and Head.
NO
Replace the FL301 or the
Q301.
3-12
5. SYSTEM/KEY CIRCUIT
(1) AUTO STOP
Auto Stop
YES
Does the SW30 waveform NO Check the Drum Motor
appear at the IC501 signal.
Pin 24?
YES
NO Do T/UP Reel Pulses NO
Do the T-UP Reel Pulses Does 5.0V appear at the
appear at the Q514
appear at the IC501 Pin 99? RS501?
Base terminal ?
YES YES YES NO
Replace the T/UP Reel Check the Q154 Power
Replace the IC501.
Sensor (RS501). Circuit.
(2) The unstable loading of a Cassette tape
The unstable loading of a
Cassette tape
YES
Is 12V applied to the NO Refer to "SMPS CAPSTAN
IC502 Pin 9? 12 Volt Trouble Shooting".
YES
Does the "H" signal appear NO Is 5.3V applied to the
at the IC501 Pin 67 during
R544 ?
inserting the CST ?
YES NO
YES
Does the "L" signal appear
Check the CST SW and Refer to SMPS 5.3VA
at the IC501 Pin 53 during
the peripheral circuitry. troubleshooting.
inserting the CST?
NO
YES
Does 6.2V occur at the
Check the IC501
IC502 Pin 15 during
Pins 32, 33, 34, 35.
inserting the CST?
NO
YES
Check the Deck
Replace the IC502.
Mechanism.
Caution : Auto stop can occur because Grease or Oil is dried up
3-13
(3) KEY doesn't working
KEY doesn't working.
Is 5VA applied to the IC501 NO Refer to "SMPS 5.3VA
Pin 14? Trouble Shooting".
YES
Does LED display change NO Replace the defective
when a function button is
switches.
pressed?
3-14