CHECK THE KEY BOARD AND MCU
CHECK THE HANDSET ITSELF
CHECK THE +12V SUPPLY CIRCUIT
CHECK THE IR IN/OUT CIRCUIT
CHECK THE HEADPHONE BOARD
(POWER BOARD)
IS THE +12V SUPPLY NORMAL?
IS THE REMOTE CONTROL OK?
IS THE HEADPHONE OUTPUT OK?
OK
NORMAL?
IS THE IR IN/OUT NORMAL?
IS THE REMOTE HANDSET ITSELF
NO
YES
NO
YES
NO
NO
NO
YES
YES
TROUBLESHOOTING GUIDE
NORMAL?
IS THE PRE-OUT NORMAL WHEN
INPUT IS PHONO
YES
IS THE RIAA CIRCUIT NORMAL?
IS THE MC AMP CIRCUIT NORMAL?
YES
IS THE MM MODULE OK?
IS THE INPUT LOAD SELECT NORMAL?
YES
NO
YES
NO
YES
NO
NO
NO
IS THE IDLE CURRENT NORMAL?
IS THE THD BAD?
YES
YES
NO
NO
CHECK THE MC AMP CIRCUIT
CHECK OTHER SECTION
ADJUST THE IDLE CURRENT OR
CHECK OTHER PATRS OF THE
CHECK THE INPUT SELECT CIRCUIT
CHECK THE IR IN/OUT CIRCUIT
CHECK THE IDLE CURRENT CIRCUIT
CHECK THE AMP CIRCUIT SECTION
TURN THE TRANSFORMER
CHECK OTHER AMP CIRCUIT SECTION
CHECK THE LINE MODULE
CHECK THE MM MODULE
AMP SECTION
IS THE S/N BAD?
IS THE LINE MODULE NORMAL?
YES
NO
NO
YES
YES
CHECK THE TONE DEFEAT CIRCUIT
CHECK THE MAIN TRANSFORMER AND
POWER SUPPLY ON MAINBOARD
CHECK THE VOLUME CONTROL CIRCUIT
CHECK THE RELAY CONTROL CIRCUIT
CHECK THE PREAMP CIRCUIT SECTION
CHECK ALL POWER SUPPLIES
CHECK THE LED CONTROL CIRCUIT
CHECK THE +5V SUPPLY
AND POWER SUPPLY ON MAINBOARD
IS THE TONE DEFEAT CIRCUIT
IS THE VOLUME CONTROL CIRCUIT
IS THE RELAY CONTROL HIGH LEVEL?
IS THE INPUT NORMAL?
NORMAL?
YES
YES
YES
NO
NO
NO
NO
CHECK KEY CIRCUIT
(POWER BOARD)
YES
IS IT BLUE
NO
CAN PRESSING ANY KEY TO MAKE
THE UNIT WORK NORMALLY?
IS THE 3-COLOUR-LED AMBER LIGHT?
PUSH THE POWER SWITCH TO ON
YES
YES
YES
IS THE PRE-OUT NORMAL?
SHORT WORKING
IS THERE SIGNAL OUTPUT?
IS THE 3-COLOUR-LED RED AFTER
YES
NO
YES
NO
NO
ARE ALL POWER SUPPLIES OK?
IS IT RED FLASH?
NO
NO
YES
NO
NO
YES
