4200 - Laser Scanner Unit (Pin Photo Diode Sensor) Error - Kyocera FS-1900 Service Manual

(11) 4200 - Laser scanner unit (Pin photo diode sensor) error

Meaning
Laser beam detection
failed. The pin photo
diode sensor [board]
(KP-746) does not
deliver a horizontal
synchronous
signal (PD*).
Call service
4200:0123456
Turn power switch off.
Remove and check
harness between
engine board (KP-864)
and laser scanner unit.
OK?
Turn power switch on.
+24 V DC
at #1 pin of YC601
on APC board
(KP-742) ?
Print status page.
Does
pin #4 (LASER*) of
YC601 on APC board
(KP-742) goes high and
then low?
FS-1900
Suggested causes
No laser beam due to the laser diode defect
(PD*).
Soiled or defective pin photo diode sensor.
Defective gate array U204 of engine board.
Improper connector insertion.
Defective harness between engine board and
laser scanner unit.
1
* : Pin photo diode sensor
[board KP-746] detecting
horizontal synchronization signal
Frequency: 2.7 kHz,
Low level width: 1.4 µs
No
Yes
Replace harness between
engine board (KP-864)
and laser scanner unit.
No
Yes
No
Replace engine board
(KP-864). See page 5-22.
Yes
NOTE:
If the problem is not solved by
this flow chart replace the
following items:
6-16
Corrective action
Follow the flow chart
below.
Print status page.
Pin #8 (_PDIN*)
of YC601 on APC board
(KP-742) output pulse
1
signal* ?
Yes
Replace engine board
(KP-864). See page 5-22.
Replace laser scanner
unit. See page 5-37.
Harness (S02404) scanner unit
and engine board (KP-864)
Engine board (KP-864) and scanner
unit (replace at the same time)
No