Protection Function - Canon imageCLASS X LBP1238 II Service Manual

AC input
Fuse
FU101
Fuse
FU102
Frequency detect circuit
Rectifying
circuit
Generation
circuit
Generation
Protection
circuit

Protection Function

Overview
This machine has a protection function against overcurrent and overvoltage.
Description
If overcurrent or abnormal voltage occurs due to a trouble, the DC voltage is automatically cut off to prevent damage to the Power
Supply PCBs.
The Low Voltage Power Supply has a protection function to prevent damage to the Power Supply PCB caused by overcurrent
and overvoltage.
When no DC voltage is output from the Low Voltage Power Supply Assembly, it is possible that the protection function has been
activated. Therefore, turn OFF the Power Switch, disconnect the AC Power Supply Cord from the inlet, and then fix the trouble
before turning ON the Power Switch again.
Low Voltage Power Supply
Fixing control
circuit
FREQSNS LVT
+24VA
FET
+24V
+3.3VA
+3.3V
circuit
Fixing Assembly
DC Controller
+24VD
+24VA
+3.3VC
FET
+24VC
High Voltage Power Supply
24
2. Technical Explanation (Device)
Power Switch
+3.3VB
+3.3VA
FET
+24VBSNS
+24VB
FET
Interlock switch
SW101
SW1
+24VA