1-10-1
E9NG0TR
TROUBLESHOOTING
1 Power Supply Section
NOTE: BOARD MEANS PRINTED CIRCUIT BOARD.
FLOW CHART NO.1
The power cannot be turned on.
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?
Check each rectifying circuit of secondary circuit
and replace P1(AV ASSEMBLY) if defective.
See FLOW CHART No.2 <The fuse blows out.>
Check for lead or short-circuiting of primary
circuit component and replace P3(PW/SW
ASSEMBLY) if defective.
(Q1001, Q1003, T1001, D1001, D1002, D1003,
D1004, R1043)
Yes
Yes
Yes
No
No
No
FLOW CHART NO.2
The fuse blows out.
After servicing, replace the fuse.
Check the presence that the primary component
is leaking or shorted and replace P3(PW/SW
ASSEMBLY) if defective.
Check the presence that the rectifying diode or circuit
is shorted in each rectifying circuit of secondary side
and replace P3(PW/SW ASSEMBLY) if defective.
FLOW CHART NO.3
When the output voltage fluctuates.
No
Yes
Does the secondary side photo coupler circuit
operate normally?
Check the circuit and replace P3(PW/SW
ASSEMBLY) if defective.
(IC1001, D1006, D1012, D1024)
Check the circuit and replace P3(PW/SW
ASSEMBLY) if defective.
(IC1001, Q1004, D015, D017, D1019)
FLOW CHART NO.4
When buzz sound can be heard in the vicinity of power circuit.
Check if there is short circuit on the rectifying diode and the circuit in each rectifying circuit of secondary side,
and replace P1(AV ASSEMBLY) if defective. (D013, D014, D016, D018, D019, D1008, D1016, D1030, D1031,
D1032, IC1103, IC1104, IC1800, Q1100, Q1105, Q1106, Q1110, Q1114, Q1508, Q1511, Q1513, Q1516,
Q1517, Q1520, Q1521, Q1527)
No
Yes
FLOW CHART NO.5
-FL is not outputted.
Is the supply voltage of -24V fed to the anode of
D018?
Check D018 and their periphery, and replace
P3(PW/SW ASSEMBLY) if defective.
Check for load circuit short-circuiting or leak, and
replace P1(AV ASSEMBLY) if defective.