Hitachi DVPF2E, Service Manual

Page: 22 / 112

E1-8-1
FLOW CHART NO.1
The power cannot be turned on.(1)
Is the fuse normal?
Is normal state restored when once unplugged
power cord is plugged again after several seconds.
Is the AL+5V line voltage normal?
Is each voltage of the secondary circuit normal?
See FLOW CHART No.2 <The fuse blows out.>
Check if there is any leak or short-circuit on the
primary circuit component.
(Q1001, Q1003, T001, D1001, D1002, D1003,
D1004, D1011, C1003, C1005)
Check each rectifying circuit of the secondary circuit.
Yes
Yes
Yes
No
No
No
No
FLOW CHART NO.2
The fuse blows out.
After servicing, replace the fuse.
Is there any leak or short-circuit on the primary
component?
Is the voltage of -30V supplied to the anode of
D1010?
Check if short-circuit on the rectifying diode and the
circuit in each rectifying circuit of the secondary side.
FLOW CHART NO.3
When the output voltage fluctuates.
No
Yes
No
No
Yes
Does the photo coupler circuit on the secondary
side operate normally?
Does the photo coupler circuit on the primary side
operate normally?
Check the circuit and replace the parts.
(IC1001, IC1002, D1013)
Check the circuit and replace the parts.
(IC1001, D1012, D1024)
FLOW CHART NO.4
When buzz sound can be heard in the vicinity of the power circuit.
Check if there is any short-circuit on the rectifying diode and the circuit in each rectifying circuit of the secondary side.
(D013,D015,D1005,D1008,D1009,D1010,D1016,D1030,IC1041,IC1052,Q051,Q053,Q055,Q056,Q1052,Q1054,Q1055,Q1057)
FLOW CHART NO.5
AL-30V is not outputted.
Is the "L" pulse inputted to the base of Q053? Is the "H" pulse inputted to the base of Q054?
Check D1010 and their periphery.
Check if there is any leak or short-circuit on the
loaded circuit.
No
No
Yes
Yes
FLOW CHART NO.6
PON 44V is not outputted.
Is 44V voltage outputted to the emitter of Q053?
Check D013, C013 and their periphery.
Replace Q053.
Yes
Replace Q054.
No
Replace IC501.
TROUBLESHOOTING
[ POWER SUPPLY SECTION ]