FUNAI LC195SLX - Troubleshooting; Power Supply Troubleshooting

8-1 A91N3TR
TROUBLESHOOTING
[ Power Supply Section ]
The power cannot be turned on.
The fuse blows out.
FLOW CHART NO.1
FLOW CHART NO.2
Is normal state restored when once unplugged
power cord is plugged again several seconds?
Check if there is any leak or short-circuiting on the
primary circuit component, and service it if defective.
(D601, D602, D603, D604, Q601, Q602, T601)
Ye s
No
Ye s
Is the fuse (F601) normal?
See FLOW CHART No.2 <The fuse blows out.>
No
Ye s
Is the INV+31V line voltage normal?
No
Check each rectifying circuit of the secondary
circuit and service it if defective.
Check the presence that the primary component
is leaking or shorted and service it if defective.
Check the presence that the rectifying diode or circuit
is shorted in each rectifying circuit of secondary side,
and service it if defective.
After servicing, replace the fuse.
When the output voltage fluctuates.
FLOW CHART NO.3
Does the photocoupler circuit on the
secondary side operate normally?
No
Ye s
Check IC601, D633, Q631 and their periphery
circuit, and service it if defective.
When buzz sound can be heard in the vicinity of power circuit.
FLOW CHART NO.4
Check if there is any short-circuit on the rectifying diode and the circuit
in each rectifying circuit of the secondary side,
and service it if defective. (IC631, Q201, Q205, Q206, Q634, Q635, Q636, Q637, Q640, Q641, Q643, D631, D632, D636,
D638, D639, D641, D643)
Check if there is any leak or short-circuit on the loaded
circuit, and service it if defective.
INV+31V is not output.
FLOW CHART NO.5
Is approximately +31V voltage supplied to the
cathode of D632?
No
Ye s
Check C632, D632, D633 and their periphery
circuit, and service it if defective.
Check IC601, D608, D610 and their periphery,
circuit and service it if defective.