Oki B 4100 Maintenance Manual page 259

(4) No 24 V output
Start
Is there oscillation
waveform at VCE of Q1?
Is the voltage across
C22 at 24 V or more?
Is the voltage across
C23 at 24 V or more?
End
40055101TH Rev.4
No
Yes
No
Yes
No
Yes
1. Q1 short circuit
2. Q3 short circuit
Replacement
3. R9 open circuit
4. D8, D9 or D10 short circuit
1. ZD7 or ZD8 short circuit
2. C22 short circuit
3. ZD5 short circuit
Replacement
4. Check any short circuit on the load side.
5. D9 open circuit
1. Q4 open circuit
2. R24 open circuit
Replacement
3. ZD3 or ZD4 open circuit
259 /