6-2
L0370TS
1. POWER SUPPLY SECTION
Check IC601,D612,D613,D615 and their periphery,
and service it if defective.
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.
(Q601,Q603.T601,D605,D606,D607,D608,C605,
C606,C610,C654)
Yes
No
Yes
Is the fuse (F601) normal?
See FLOW CHART No.2 <The fuse blows out.>
No
Yes
Is the AL +3.3V 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
Yes
Check IC601,D646,D649 and their periphery, 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. (IC603,IC604,D630,D631,D632,D633,D635,D645)
Check if their is any leak or short-circuit on the
loaded circuit, and service it if defective.
AL-8V is not outputted.
FLOW CHART NO.5
Is approximately -8V voltage supplied to the
anode of D631?
No
Yes
Check D631 and the periphery circuit, and service
it if defective.
