Sharp MX-4100N Service Manual page 490

D. Automatic pressure release system
The upper and the lower heat rollers are normally pressed together.
When, however, one of the following conditions is satisfied, pres-
sure is released.
• When the machine shifts to the pre-heating mode.
• When the machine shifts to the auto power shut off mode.
• When the power switch of the operation panel is turned OFF.
• When the machine has been left in the ready state for 20 min-
utes.
• When the envelope mode is used.
(1) Pressure release operation
The pressure release motor (PRM) rotates to drive the pressure
release lever of the fusing unit to the pressure release state via the
reduction gears (6 pcs.).
When 3600ms passes from operating the pressure release detec-
tion level and driving the pressure release sensor (HLPCD) to the
transmission state (L level), the pressure release motor stops to
complete the pressure release operation.
Pressing condition
Pressure release
motor (PRM)
Pressure release
state
(2) Pressing operation
When an end use performs any operation or when the machine
receives a job signal, the pressure release motor rotates reversely
to dive the pressure release lever to the pressing state.
When 200ms passes from when the pressure release sensor
(HLPCD) is in the interruption state (H level), the pressure motor
stops to complete the pressing operation.
NOTE: When turning OFF the main power switch of the machine,
be sure to turn OFF the power switch of the operation
panel and wait for 10 sec from turning OFF the LCD, and
then turn OFF the main power switch.
If the main power switch is turned OFF with the LCD dis-
played, the power is turned off without completion of the
pressure release operation. This will deform the upper and
the lower heat rollers.
When, in addition, the fusing roller is installed again after
removing it, be sure to install it under the pressure release
state.
Pressure release lever
MX-5001N FUSER SECTION M – 3
3. Disassembly and assembly
A. Fusing unit
c
a
a Upper thermostat
b Lower thermostat
c External thermostat
d Upper heater lamp
e Lower heater lamp
f External heater lamp
1) Open the right door.
2) Remove the blue screw and the step screw. Release the lock
lever and remove the fusing unit.
1
1
f
f
c
e
d
b
Parts
2
2
3
1