Kyocera FS-1920 Service Manual page 56

2FP/2FY/2FR
Code
4000 Laser scanner unit (Polygon motor)
error
• POLRDY* does not go low within 20
seconds after POLON* goes low (When
starting) or within 16 seconds after
REGPAP signal goes high (during
printing).
Call service
4000:01234546
Turn power switch off.
Remove and check
harness between
engine board (KP-1081)
and laser scanner unit.
Turn power switch on.
at #33 pin of YC7
on engine board
Print status page.
pin #29 (POLCLK) of
YC7 on engine board
(KP-1081) output
square-wave*
1-5-6
Contents
START
No
OK?
Yes
+24 V DC
No
(KP-1081) ?
Yes
Does
No
1
signal?
Yes
1
* : 2.7165 KHz
Causes
Defective gate
array U7 on the
engine board.
Defective poly-
gon motor.
Improper connec-
tor insertion.
Defective har-
ness between la-
ser scanner unit
and engine board.
NOTE:
When If not solved this flow
chart, try to replace below
items.
Harness (S03012) scanner
unit and engine board (KP-
1081)
Engine board (KP-1081) and
scanner unit (replace at the
same time)
Replace harness between
engine board (KP-1081)
and laser scanner unit.
Replace engine board
(KP-1081). See page 1-6-
20.
Remarks
Check procedures/corrective measures
Follow the flow chart below.
NOTE:
Pins of YC7 connector are crowded
and tiny. When if measuring signal,
contact measurement probe with
pins of YC7 connector accurately.
Print status page.
Does
pin #31 (POLON*) of
YC7 on engine board
(KP-1081) goes high
and then low?
Print status page.
Does pin
#30 (POLRDY*)
of YC7 on engine board
goes low, after pin #31
(POLON*) of YC7
goes low?
Replace engine board
(KP-1081). See page 1-6-
20.
Replace laser scanner
unit. See page 1-6-35.
No
Yes
No
Yes