Lexmark W812 - Engine Board <-> LVPS <-> Interlock SW and Fan (3;3)

5-20 Service Manual
4022-XXX
Engine Board <−> LVPS <−> Interlock SW and Fan (3/3)
• Cutting off the 24V dc power by the Interlock switch
When the Cover Popup is opened, the contact of the Interlock SW is also opened,
and the 24V dc power circuit from the LVPS to the Engine Board is then opened. As
a result, the supply of the power from the PWBA Engine Board to the Motor, Clutch,
and Solenoid is stopped. However, the 24V dc is directly supplied from the LVPS to
the fan, and it is not cut off even if the contact of the Interlock SW is opened.
• Stopping the output of 24V dc power by fan control
When the Engine Board stops the fan control signal that instructs the low- or high-
speed rotation of the fan, the fan stops, and stops the output of the 24V power from
the LVPS to the Engine Board. The standby current of the 24V circuit is then cut off,
and the power consumption is saved at a minimum.
Engine Board <−> Fuser Assembly and LVPS (1/2)
P/J152
A1
A2
A3
A3
A4
A5
P/J151
A2
A1
A4
A5
3
4G
1G
1G
4G
3
L
N
N
P/J272
1
3
L
N
N
N
L
LG
STS
/EXIT
LG
Pullup3.3V
Line
Neutral
/EXIT
LG
Pullup3.3V
LG
STS
3
21
P/J153
Exit
Sensor
Temperature
Sensor
Thermostat
Heat Roll
Fuser Asm
FG
ENGINE
BOARD
P/J15
1
2
3
4
5
1
2
4
3
2
1
/HEAT
3.3VDC
P/J271
P/J27
LVPS
Fuser
Control