Canon LBP-CX Series Service Manual page 150

Warning:
Never unplug any connector unless the power is OFF. This can destroy the laser chip.
Note:
1. Confirm that the laser power checker operates normally before making adjustments.
2. If the laser output is adjusted incorrectly, the laser will be damaged. In any case, the output should be adjusted
as seldom as possible.
3. Output power of the laser should be within the range indicated on the laser unit label.
4. Check the laser output power after replacing the DC controller PCB, the laser unit, if the print is faint or lines
on the print are thin, if lines are too wide, if the laser intensity decreases, or if the laser beam stops.
5. Turn VR202 slowly on the DC controller PCB.
6. Measurement should be made three times and averaged.
7. If the laser unit or DC controller PCB is replaced, turn VR202 fully counterclockwise and adjust laser beam
intensity.
After confirming that power is
switched
0
FF, connect the
printer driver and laser driver
checker (RY9-0002). (See
Figure 7-9.)
Set the laser power checker
(TKN-0198) on the laser and
scanner unit.
Follow flowchart 1 and return.
Follow flowchart 2 and return.
Follow flowchart 1 and return.
Replace the laser unit.
Follow flowchart 1 and return.
Adjustment finished.
YES
YES
Figure 7-12 Basic flowchart
Printer driver
and I aser driver Connector
checker (l 0 pin)
DC controller PCB
TEST
PRINT
J205
Connector (7 pin)
J209
Connector (8 pin)
No connection
Figure 7-9
Figure 7-10
VIDEO
SELECT
LASER READY LASER LASER
PCOHWECERK CONTROL POWER CURRENT
SELECT
IQ
qy
E N A B W H·UNE
0
<iY
<NH
0
~,.GH
<iY
MAX
~
+
e~L~:~
NOA -MED STO
~
,Low
g-
Figure 7-11 Printer driver and laser driver checker control panel
COPYRIGHT
©
BY CANON INC. CANON LBP-CX SERIES REV.2 JULY 1985 PRINTED IN JAPAN (IMPRIME AU JAPON)
a. Flowchart 1
Note: Laser power does not change
if VR202 is turned while the
laser power check button is being
pressed. Be sure to turn VR202
before pressing the laser power
check button.
If VR202 is turned too far clock·
wise and the laser power button
is pressed, the laser chip may be
damaged. VR202 rotation should
be within 5°.
From the Basic Flowchart
Switch the power ON.
Measure the output of the laser
power checker while pressing the
laser power check button on the
printer driver and laser driver
checker.
Turn VR202 a little clockwise
without pressing the laser power
check button.
Measure the output of the I aser
power checker while pressing the
laser power check button.
If the READ/WAIT indicator does not light
after 180 seconds, switch the power ON
again. If the READY /WAIT does not light
within 180 seconds after this, correct the
malfunction noted in the status indicator
(See IV in this chapter.)
YES
NO
Adjustment finished
Turn VR202 a little counterclockwise
without pressing the laser power
check button.
Measure the output of the I aser
power checker while pressing the
laser power check button.
NO
Turn VR202 fully counterclockwise.
Switch the power OFF, and return
to the Basic Flowchart.
Figure 7-13
7-9