Epson AcuLaser C8500 Service Manual page 536

EPSON AcuLaser C8500
Table 7-5. Signal Description - § § § § 1
Signal line
Control signal for P/R HEATER and H/R HEATER on/
HEATER ON(L) 5VDC
off.
Detection of interlock connector, interlock switches,
24VDC-I/L
and the LVPS relay control signal.
5VDC-LD Supply voltage of the LD ASSY of the ROS ASSY.
Scanning start reference signal based on input of light
SOS
to SOS SENSOR of laser beam SOS PWB.
VREF Reference voltage for target value for laser power.
Control signal for LD on-enable / force off.
LD ENB
(High: Force off, Low: On enable)
SCANNER MOTOR ON(L)
On/off control signal for scanner motor of ROS ASSY.
5VDC
Mode control signal for LD power control (APC).
PCONT
(Low: Sample mode, High: Hold mode)
Pixel data signal that effects LD emission.
VDATA
(High: LD on, Low: LD off)
FRONT COVER SWITCH FRONT COVER open (off) / closed (on) detection
ON(L) 5VDC signal by FRONT COVER SWITCH L.
APPENDIX
Description
Wiring Diagrams and Signal Information
LVPS excess current protection circuit
All output is shut off when 24VDC/5VDC supply voltage is shorted. After
restoring the short, reset the printer by turning the power off and then, after
waiting 2 to 3 minutes, back on.
LVPS excess voltage protection circuit
All output is shut off when 24VDC/5VDC supply voltage is shorted. The
operation point at this time is 7VDC or less for 5VDC, and 27 - 36VDC for
24VDC (reference). Reset the printer by turning the power off and then,
after waiting 2 to 3 minutes, back on.
Output interruption by FRONT COVER SWITCH R
When FRONT COVER SWITCH R trips, the "24VDC-I/L" circuit is
interrupted, shutting off 24VDC power supply to the MCU PWB and 5VDC-
LD power supply to the ROS ASSY (LD ASSY).
When FRONT COVER SWITCH R is on, 24VDC-I/L is supplied to the
LVPS relay circuit, and 24VDC and 5VDC-LD is output by the LVPS.
FRONT COVER SWITCH R is also the interlock SWITCH for the 5VDC-LD
circuit.
W A R N I N G FRONT COVER SWITCH R and the TOP COVER SWITCH are
interlock switches for laser radiation. To avoid exposure to
laser radiation, never turn on both of these two interlock
switches simultaneously (except during regular operations)
or short the circuit to effect laser emission. Exposure to
laser radiation could result in blindness. Be sure to follow
the procedures described in this Service Manual for tasks
requiring the printer operation during servicing.
Revision C
7-34