– 75 –
MD-X60H
• Although HF waveform is normal and time
indication is normal, no sound is not output.
Check the IC2 pin 58 (EFLG).
Check the IC2 pin 56.
Check IC501 and POWER AMP. IC201.
Yes
Yes
No
Usually, the number of pulses of flawless disc is 100 pulses/sec or
less.
TROUBLE-SHOOTING (AMP SECTION)
• When the power supply is turned off (POWER
OFF), and the "PROTECT" blinks
Is IC901 pin 45 PROTECT input in Low
state?
Yes
The pin 45 of IC901 keeps High state,
and normal rise is ensured.
Monitoring the IC901 pin 45, press the
POWER key to turn on the power
supply again.
Monitor the Q297 collector when the
power supply is on.
Is the state changed from H to L?
No
The state of pin 45 of IC901 is changed from H to L, and the power supply is turned off
again, resulting in "PROTECT" error.
Is Q260 in ON
state?
Yes
Check IC201
and Q260.
No
Is Q297 collector
voltage 0V?
Yes
Check IC201,
Q297 and Q298.
Yes
Error due to DC detection
Check IC201.
Check the power circuit.
Is Q251 collector
voltage 0V?
Yes
Check Q251.
Yes
Error due to Lch side overcurent detection
Check for short-circuiting on the L-ch side
SP terminal and subsequent parts.
Monitor the Q251 collector when the
power supply is on. Is the state
changed from H to L?
Check Q252.
Yes
Error due to Rch side overcurent detection
Check for short-circuiting on the R-ch side
SP terminal and subsequent parts.
Monitor the Q252 collector when the
power supply is on.
Yes
The pin 45 of IC901 keeps High state, and
normal rise is ensured.
Error due to detection of abnormal
temperature rise in IC201After
cooling the set turn on the power
supply again.
The state of pin 45 of OC901 is changed from H to L, and the power supply is turned off
again, resulting in "PROTECT" error. Check IC201.
No
No
No
No
No
Yes
No
No
No
Содержание MD-X60H
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