CD73
COMPACT DISC PLAYER
- 25 -
TROUBLESHOOTING GUIDE
SET POWER SWITCH TO ON.
IS POWER TURNED ON ?
CHECK FUSES
FS501-FS504 OPEN ?
FS501-FS504 DEFECTIVE
CRYSTAL X401 DEFECTIVE.
MICROPROCESSOR IC U701 DEFECTIVE.
MOTOR DRIVE IC U102 DEFECTIVE.
CAN TRAY BE OPENED ?
CAN TRAY BE CLOSED ?
DOES INITIAL READING OCCUR ?
CAN DISC BE PLAYED ?
CHECK TRACKING SERVO CIRCUIT CORRECT ?
SERVO IC U101 OR U201 DEFECTIVE.
CHECK DISC OR MECHANISM AND CONNECTOR
CHECK OUTPUT PULSE AT PIN 61,62,63 OF U201
CHECK OUTPUT SIGNAL AT PIN 13,16 OF U401
AUDIO OUTPUT IS CORRECT ?
IS POWER SUPPLY NORMALLY ?
CHECK POWER SUPPLY PATTERNS.
OK
CHECK POWER SUPPLY
CIRCUIT NORMAL ?
IC U401 DEFECTIVE.
CHECK OUTPUT SIGNAL AT PIN 1,7 OF U403-U405
IC U403, U404 OR U405 DEFECTIVE.
CHECK MUTE CIRCUIT Q407, Q408, Q409, Q410
LINE OUT PLUG OR PATTERNS DEFECTIVE.
MUTE CIRCUIT DEFECTIVE.
IC U201 DEFECTIVE.
M101 SWITCH, DEFECTIVE
OR PATTERN AND CONNECTOR OPEN.
IS OSCILLATOR CIRCUIT
OSCILLATING ?
POWER SUPPLY PATTERNS OPEN
OR U501-U507 DEFECTIVE.
IS THERE OPEN/ CLOSE KEY SIGNAL
INPUT ? U701 PIN 39, 40
IS LOADING MOTOR DRIVE CIRCUIT
OPERATION NORMAL ?
CHECK OPEN/ CLOSE SIGNAL AT U701
PIN 40
PIN 39
TRAY OPEN
H
L
TRAY CLOSE
L
H
LOADING MOTOR AND LEAD WIRE DEFECTIVE
OR LOADING PART OF MECHANISM DEFECTIVE.
CHECK LASER LIGHT ?
DOES LENS MOVE UP AND DOWN ?
RF SIGNAL OUTPUT ?
U101 DEFECTIVE.
FEED MOTOR OR WIRING DEFECTIVE.
CHECK FOCUS SIGNAL OUTPUT ?
U101 DEFECTIVE.
CHECK CONNECTION OR PICKUP.
CHECK LASER CIRCUIT CORRECT ?
CONNECTION OR PICKUP DEFECTIVE.
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
YES
YES
YES
YES
YES
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
CHECK CLOCK PULSE AT PIN5 OF U401
M302 OR U402 DEFECTIVE.
YES
NO
NO
NO
NO
NO