Trouble Sh ooting
Page 11
A LC502
9. No power on
9.1 No power on (I)
Check output v5V,
+15V is right or not.
NG
OK
Check power switch is turn on
or not.
OK
NG
Check power cord ( P801), Signal cable
(P302),P802, P803, CN102, CN103
is connected right or not.
It is not power board
problem.
Turn switch on.
OK
NG
Check C805 is about DC
140V-330V or not.
Connect it right.
OK
NG
Check C807 is over
10V or not.
Check F801, D801, P801
and repair them.
OK
NG
Check pin 6 of I801 have
same pulse or not.
Check R805, R803, I801
and repair them.
OK
NG
Check pin 1 of T802 have
same pulse or not.
Check peripheral components
of I801 and repair them.
OK
NG
Check peak voltage of R811 triangle
pulse is up to 1 volt or not.
Check Q803, R813, R814, D806
, R812 and repair them.
OK
NG
Check D809, D810, C816, C821, T802
have same short circuit, or the output
+5V, +15V is over load.
Check D804, R807 and
repair them.
NG
OK
Check feedback circuit around I802,
I803 and the other components
and repair them.
Repair them.
