Oki OKIFAX 5750 Maintenance Manual page 806

Action Item:
No.
1
Probable cause 1:
Check item 1:
Probable cause 2:
Check item 2:
2
Probable cause 1:
Check item 1:
Probable cause 2:
Check item 2:
3
Probable cause 1:
Check item 1:
4
Probable cause 1:
Check item 1:
Probable cause 2:
Check item 2:
5
Probable cause 1:
Check item 1:
6
Probable cause 1:
Check item 1:
Probable cause 2:
Check item 2:
7
Probable cause 1:
Check item 1:
Probable cause 2:
Check item 2:
8
Probable cause 1:
Check item 1:
9
Probable cause 1:
Check item 1:
Probable cause 2:
Check item 2:
10
Probable cause 1:
Check item 1:
11
Probable cause 1:
Check item 1:
12
Probable cause 1:
Check item 1:
41285901TH Rev.3
D129 is defective.
Replace D129.
The load is larger than the normal value.
Check if the load current is 2µA or less.
LSI or OSC is defective.
Check the PWM waveform of DB output.
Q106 is malfunctioning.
Replace Q106
LSI or OSC is defective.
Check the PWM waveform of TR1 output.
T2 is defective.
Replace T2.
LSI or OSC is defective.
Check the PWM waveform of TR1 output.
T2 is defective.
Replace T2.
DD117, D118 or DD135 is defective.
Check if these diodes are IZB 390.
LSI or OSC is defective.
Check the PWM waveform of TR2 output.
The class of D124 or D125 is incorrect.
Check if both D124 and D125 are of EB-2 class.
The load current is lower than the specified value.
The load current shall be 10 to 20µA. (Namely, the load current shall not be more
than or less than this limit range.)
LSI or OSC is defective.
check the PWM waveform of CH output.
HEAT-NO remains at "L".
Check whether the collector of Q7 becomes "H".
If Q7 is "L", go to the probable cause 2.
If Q7 is "H", other board may be damaged.
IC4, Q6, or Q7 is defective.
Replace IC4, Q6 or Q7
If the problem is unsolved, other board may be damaged.
SW2 is defective.
Replace SW2
If the problem is unsolved, other board may be damaged.
PS1, PS2, PS3 or PS4 is defective.
Replace PS1, PS2, PS3 or PS4.
If the problem is unsolved, other board may be damaged.
PS6 is defective.
Replace PS6
If the problem is unsolved, other board may be damaged.
ACTION
806 /