NAD C 542 Service Manual

Also see for C 542: Catalog Owner's manual Owner's manual

Contents

NAD C 542 Service Manual Manual pdf 23 page image

- 23 -TROUBLESHOOTING GUIDESET POWER SWITCH TO ON.IS POWER TURNED ON ?CHECK FUSESM507, M512-M514 OPEN ?M507,M512-M514 DEFECTIVE CRYSTAL X301 DEFECTIVE.MICROPROCESSOR IC U401 DEFECTIVE.MOTOR DRIVE TRANSISTOR Q104,Q105, Q106, Q107 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 U202 DEFECTIVE.CHECK DISC OR MECHANISM AND CONNECTORCHECK OUTPUT PULSE AT PIN 61,62,63 OF U201CHECK OUTPUT SIGNAL AT PIN 13,16 OF U302AUDIO OUTPUT IS CORRECT ? IS POWER SUPPLY NORMALLY ? CHECK POWER SUPPLY PATTERNS.OKCHECK POWER SUPPLYCIRCUIT NORMAL ?IC U302 DEFECTIVE.CHECK OUTPUT SIGNAL AT PIN 1,7 OF U305, U306 IC U305 OR U306 DEFECTIVE.CHECK MUTE CIRCUIT Q301, Q302, Q303, Q304LINE OUT PLUG OR PATTERNS DEFECTIVE.MUTE CIRCUIT DEFECTIVE.IC U201 DEFECTIVE.M101 SWITCH, DEFECTIVEOR PATTERN AND CONNECTOR OPEN.IS OSCILLATOR CIRCUITOSCILLATING ?POWER SUPPLY PATTERNS OPENOR U501-U507 DEFECTIVE.IS THERE OPEN/ CLOSE KEY SIGNALINPUT ? U401 PIN 66, 65IS LOADING MOTOR DRIVE CIRCUITOPERATION NORMAL ?CHECK OPEN/ CLOSE SIGNAL AT U401PIN 65 PIN 66TRAY OPEN H LTRAY CLOSE L HLOADING MOTOR AND LEAD WIRE DEFECTIVEOR 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.YESYESYESYESYESYESYESYESNONONONOYESYESYES YES YESNOYESYESYESYESYESYESYESYESYESNO NO NONONONONONONO NONONONOCHECK CLOCK PULSE AT PIN4 OF U302 M302 OR U302 DEFECTIVE.YESNONONONONO