Trouble Sh ooting
Page 15
A LC502
12. Checking the audio circuit
Is a cable with the
host PC connected?
OK NG
Failure point
Audio cable disconntction.
Aren't the setups of the
host PC a minimum and off?
OK
NG
Failure point
The setup of the host PC is changed.
Is correct output waveform
being inputted from JK011
pin 2, 3 of the host PC?
OK
NG
Is the waveform which is the
same as JK011 being
inputted to I001 pin 4, 9?
Failure point
Audio cable disconntction.
OK
NG
Failure point
1) Printed wire broke between JK011 pin 2, 3 and I001 pin 4, 9.
2) R040, R041 open.
3) R042, R043 short.
4) C040, C041 open.
Is output wavefrom being
outputted in I001 pin 14, 17?
OK
NG
Is 15V supplied to I001 pin 15, 16?
OK
NG
Failure point
1) Speaker cable disconnection
2) Speaker failure
Proceed section 9.1 "No power on".
Is mute/STD-BY low level at pin 11,
pin 12.
OK
NG
Proceed section 11 "Checking
the operation of CPU".
Is Variable DC volume
control at pin 6.
OK
NG
Check I002 pin 8 is 5V DC.
Proceed section 11 "Checking
the operation of CPU".
OK
NG
Proceed section 9.1 "No power on".
Failure point
I001 failure.
