Service manual

Page 24
AL1702
12. Power Board
Check output voltage +5V, +12V and 22V
is right or not.
No
Yes
Check power switch is turn on or not.
Yes
No
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.
Yes
No
Check C805 is about DC140V-330V
or not.
Connect it right
Yes
No
Check C807 is over 10V or not.
Check F801, D801, P801 and repair
them.
Check pin 6 of I801 have same
pulse or not.
Check R805, R803, I801 and repair
them.
Check pin 1 of T802 have same
pulse or not.
Check peripheral co,of I801 and
repair them.
Check peak voltage of R811 triangle
pulse is up to 1 volt or not.
Check Q803, R813, R814, D806,
R812 and repair them.
Check D804, R807 and repair them.
Check D809, D810, D811, C818,
C817, C822, T802 have same short
circuit, or the output +5V/+12V/+22V
is over load.
Yes
No
Yes
No
Yes
No
Yes
No
Check feedback circuit around I802,
I803 and the other components and
repair them.
Yes
Repair them.
No