NAD C316BEE, Service Manual, Page: 23 / 34

TROUBLESHOOTING GUIDE
PUSH THE POWER SUPPLY
IS THE AMBER LED AMBER
YES
NO
CAN PRESSING ANY KEY MAKE
OK
IS IT RED?
YES
CHECK THE PROTECT CIRUIT
NO
CHECK THE 5V SUPPLY CIRCUIT
(ON MAIN BOARD)
NO
NO
IS THE STANDBY SINGAL LOW
LEVEL?
CHECK THE STANDBY CONTROL
CIRCUIT
IS THE ABMER LED GREEN?
YES
NO
CHECK THE KEYS CONNECTION SOME KEYS IS USELESS?
IS THE IR CONNECTION NORMAL?
YES
NO
IS THE SPK OUT NORMAL?
YES
NO NO
CHECK THE SERVO CIRCUIT
IS THE AMP INPUT SIGNAL
YES
NO
CHECK THE POWER AMP CIRCUIT
SECTION
IS THE MUTE SIGNAL OFF?
YES
CHECK THE MUTE CONTROL
CIRCUIT OR LET IT OFF
NO
NO
YES
IS THE VOLUME CONTROL CIRCUIT
NORMAL?
CHECK THE VOLUME CONTROL
CIRCUIT
THE UNIT WORK NORMALLY?
YES
YES
NO
LIGHT?
YES
YES
CHECK THE STANDBY LED
OR IC501 PIN38
CHECK MCU AND RELAY
IS THE OUTPUT DC LEVEL
NORMAL?
ARE ALL POWER SUPPLIES OK?
CHECK THE POWER SUPPLIES
CIRCUIT
YES
NO YES
IS THERE SIGNAL OUTPUT? NORMAL?
CHECK THE TONE CIRCUIT
YES
NO
IS THE THD HIGH?
YES
IS THE IDLE CURRENT NORMAL?
IS THE S/N RATE BAD? TURN THE TRANSFORMER
ADJUST THE IDLE CURRENT OR
CHECK THE IDLE CURRENT
CIRCUIT
NO
CHECK THE POWER AMP CIRCUIT
(IF SOME TRANSISTORS ARE
DEFEATED)
IS THE REMOTE CONTROL OK?
OR CIRCUIT(PARTS)
NORMAL?
ANOTHER REMOTE CONTROL
NO
NO
YES
YES
CHECK THE IR CONTROL CIRCUIT
(INCLUDE THE IR RECEIVER AND
YES
NO
NO
YES
YES
CHECK THE IR CONNECTION
REPLACE THE BTTERIES OR
HANDSET
MCU)
IS THE REMOTE HANDSET ITSELF
SWITCH TO ON
NO
IS IT GREEN?
YES
CHECK THE STANDBY LED
OR IC501 PIN39
OR OTHER POINTS CONCERNED
TO DC OUTPUT
IS THERE
SELF-OSCILLATION SIGNAL?
NO
FIND OUT AND GET RID OF IT
YES