Oki OKIFAX 5400 Maintenance Manual page 217

ACTION Item:
No.
16 Check item 1:
17 Probable cause 1: D1 is detective.
Check item 1:
Probable cause 2: The D1 drive circuit is defective.
Check item 2:
40838301TH Rev.1
Check the PWM waveform of CH (cycle: 42µs, ON time: 36µs).
Check if both D1 and T1 or D1 and T2 are shorted.
Check PC1. [Whether PC1 turns ON or OFF according to the level of HEAT
signal (CN3-B7)?]
Check if R2 or R3 is in open state (This cannot be observed from the
external appearance because these resistors are fusible resistor.)
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ACTION