SERVICE MANUAL - Encompass Imaging

[ Power Supply Section ]
FLOW CHART NO.1
The power cannot be turned on.
Is normal state restored when once unplugged
power cord is plugged again several seconds?
FLOW CHART NO.2
The fuse blows out.
Yes
TROUBLESHOOTING
Is the fuse (F601) normal?
No
See FLOW CHART No.2
Yes
Yes
Is the INV+31V line voltage normal?
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.
After servicing, replace the fuse.
FLOW CHART NO.3
When the output voltage fluctuates.
Does the photocoupler circuit on the
secondary side operate normally?
Yes
Check IC601, D608, D610 and their periphery,
circuit and service it if defective.
FLOW CHART NO.4
When buzz sound can be heard in the vicinity of power circuit.
No
No
No
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)
Check the presence that the rectifying diode or circuit
is shorted in each rectifying circuit of secondary side,
and service it if defective.
Check IC601, D633, Q631 and their periphery
circuit, and service it if defective.
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)
FLOW CHART NO.5
INV+31V is not output.
Is approximately +31V voltage supplied to the
cathode of D632?
Yes
Check if there is any leak or short-circuit on the loaded
circuit, and service it if defective.
No
Check C632, D632, D633 and their periphery
circuit, and service it if defective.
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