Door Open Detection; Low Voltage Power Supply Control - Canon imageCLASS X LBP1238 II Service Manual

Door Open Detection

Overview
This machine uses the Front Cover Switch (SW101) of the High Voltage Power Supply PCB (UN22) to detect whether the Front
Cover is opened or closed.
Description
Symbol
UN22 High Voltage Power Supply PCB
SW101 Front Cover Switch
When door open is detected by this switch, the DC Controller stops drive of the motors and the solenoids.

Low Voltage Power Supply Control

Overview
This circuit converts the AC voltage to DC power supply and provides it to each load.
Description
The following shows a block diagram of the low voltage power supply.
• Low voltage power supply: Generates the DC power supply needed inside the printer. It also controls the temperature of the
Fixing Heater of the Fixing Assembly.
The low voltage power supply starts to operate when the AC power supply is connected to the inlet. The AC power supply is
converted to +24 V, which is the DC power supply required by the printer, and +3.3 V.
UN22
Name
When the switch has failed, the PCB needs to be replaced.
SW101
Remarks
23
2. Technical Explanation (Device)