Oki B4100 - Manual (Page 256)

40055101TH Rev.4 256 /
7.1.17 Power Supply Unit
(1) The main power supply is not turned ON.
Start
Replacement
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
To flowchart
(2) for no 5 V(S)
output.
Replacement
Replacement
Replacement
1. Breakdown of Q5
by short circuit.
1. Breakdown of Q5
in open mode.
1. PC2 fault
2. R25, R26 open circuit
1. Short or open circuit
of D1 to D4
2. Open circuit of TH1
Is the MPON
set to high?
Is the VCE voltage of
Q5 set to almost 0 V?
Is the voltage across
C26 at 4.8 V or more?
Is the triac side of
PC2 set to ON?
Is the voltage applied
across C6 at 140 V
or more?
End