Sharp FO-4500, Service Manual

Page: 53 / 192

2. Printer trouble detection
(1) Paper jam
The printer recognizes if paper remains inside the printer by detecting
the status of the Paper Take-Up Sensor (PC1) and the Paper Exit
Sensor (PC3). A paper jam is detected by the timing that PC1 and
PC3 become activated or deactivated.
When a paper jam is detected, the drive for all elements is stopped
except for the Fan Motor (M3) , excluding the two following cases.
•
During multi printing
When condition 1 listed below is detected and paper remains in the
printer, all elements except the Fan Motor (M3) will be stopped
after the paper is fed out of the printer.
•
During single printing
When condition 1 listed below is detected and paper does not
remains in the printer, elements except the Heater Lamp (H1) and
Fan Moter (M3) will ve stopped.
1. The Paper Take-Up Sensor (PC1) does not activate within 2
sec, after the Paper Take-Up Roller in the printer starts rotating,
or within 4 sec. after the Paper Take-Up Roller in the optional
250 Sheet Second Tray starts rotating.
2. The Paper Take-Up Sensor (PC1) activates when the Power
ON/OFF Switch (S1) is turmed ON, or when the Upper Unit is
closed.
3. The Paper Exit Senspr (PC3) activates when the Power
ON/OFF Switch(S1) is turned ON, of when the Upper Unit is
closed.
4. The Paper Take-Up Sensor (PC1) does not deactivate within 11
sec. after the paper leading edge reaches the Paper Take-Up
Sensor (PC1).
5. The Paper Exit Sensor (PC3) does not activate within 3.5 to 4.5
sec. after the paper leading edge reaches the Paper Take-Up
Sensor (PC1).
6. The Paper Exit Sensor (PC3) does not deactivate within 3.4 to
4.7 sec. afer the paper trailing edge passes the paperTake-Up
Sensor (PC1).
(2) Laser malfuction
All elements except the Exit Fan Motor (M3) are deactivated when the
malfunctions described below are detected.
The LDVR1 signal or LDVT2 signal deviates from the specified value
while the laser power is adjusted.
LDVR1/LDVR2 : These signals are to adjust the laser drive current.
(3) Polygon motor malfunction
1. The SSCAN signal has not been entered once within 1 sec. after
the Polygon Motor is energized.
2. The number of Polygon Motor rotations has not stabilized within
±
by 4.2 sec. after the Motor is energized.
3. The number of Polygon Motor rotations has exceeded
±
3% for
more than 0.5 sec. after the Motor is energized and the rotation
number stabilizes within
±
0.5%.
(4) Fusing malfunction
1. The temperature detected by the Thermistor has not risen 20˚C for
50 mmsec. within 12 to 30 sec. after the warming up. (This detec-
tion applies only when the Thermistor detecting temperature is
90˚C or less.)
2. The Thermistor detecting temperature has not reached to 172˚C
within 60 sec. after warming up.
3. Except in the Pause Mode*, the Thermistor detecting temperature
during the idle state has fallen to 80˚C or lower for 50 msec., or
the temperature during printing has fallen to 133˚C or lower.
4. The Thermistor detecting temperature has exceeded 193˚C for 50
msec. during temperature control.
*Pause Mode : During this mode, the control temperature is de-
creased to save power during the idle state, the
Heater Lamp being turned OFF.
(5) Exit fan malfunction
The voltage equivalent to the current*
1
of the Exit Fan Motor remains
160 mV or lower for 2 sec.
*1: detected by converting the Motor current into voltage.
How to Reset these malfunctions
Turn OFF The Power ON/OFF Switch (S1).
FO-4500H
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