Troubleshooting Guide - NAD C 546BEE Service Manual

TROUBLESHOOTING GUIDE

PLUG IN
NO NO
Is Power LED light? Check fuse F101
YES
FUSE DEFECT IS OSCILLATOR CIRCUIT OSCILLATING?
YES
YES
IS POWER TURNED CHECK FUSE
NO NO
ON? FC201,FC202,FC203,
FC204,FC205
YES
Is there open/close key signal
NO
Can Tray be opened?
input?IC206 PIN58,59
YES NO
YES
Can Tray be closed?
CHECK OPEN/CLOSE SIGNAL AT IC206
PIN58 PIN 59
TRAY OPEN H L
TRAY CLOSE L H
YES YES
IS LOADING MOTOR DRIVER CIRCUIT
OPERATION NORMAL?
YES
LOADING MOTOR AND LEAD WIRE DEFECTIVE
OR LOADING PART OF MECHANISM DEFECTIVE
NO NO
Does initial reading occur? Check laser light? Does lens move up and down?
YES
NO
IC3 Check laser
circuit correct?
DEFECTIVE
YES
YES
CONNECTION OR
PICKUP DEFECTIVE
NO NO
Check tracking servo
Can disc be played?
circuit correct?
YES
YES
Check disc or mechanism and connector
NO NO
Can USB device be
Check USB power supply normal?
read?
YES
YES
Check USB Device and connector.
Is audio output NO
Is power supply normal?
correct?
YES
CHECK CLOCK PULSE AT PIN60 OF IC701
YES
CHECK OUTPUT PULSE AT PIN34,35,36 OF IC701
YES
CHECK OUTPUT SIGNAL AT PIN16,17 OF U209
YES
YES
CHECK OUTPUT SIGNAL AT PIN1,7 OF U210,U211
YES
CHECK MUTE CIRCUIT Q210,Q211,Q212,Q213
YES
LINE OUT PLUG OR PATTERNS DEFECTIVE
OK
NO
CHECK SMPS CIRCUIT NORMAL? SMPS PATTERNS OPEN
YES
NO
CRYSTAL X201 DEFECTIVE
YES
CHECK POWER CIRCUIT POWER SUPPLY
NO
NORMAL? PATTERNS OPEN
LOADER SWITCH DEFECTIVE
NO
or
PATTERN AND CONNECTOR OPEN
MICROPROCESSOR IC206
NO
DEFECTIVE
NO MOTOR DRIVER
U202 DEFECTIVE
IC3 DEFECTIVE
NO
Check focus
NO
signal output?
YES
YES
RF signal output?
Check connector
YES
or pickup.
FEED MOTOR OR
WIRING DEFECTIVE
Servo IC701,IC703 DEFECTIVE
U11,IC1 DEFECTIVE
NO
CHECK POWER SUPPLY PATTERNS
NO
IC701/X702 DEFECTIVE
NO
IC701 DEFECTIVE
NO
U209 DEFECTIVE
NO
U210,U211 DEFECTIVE
NO
MUTE CIRCUIT DEFECTIVE
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