SERVICE MANUAL
5–64
10FEB97 – SM3226-1
Fluctuation of the Laser Diode Reference Current
Use this procedure when noise is present in flat field
images and/or images appear grainy shadowing
patterns at density transitions.
There are 3 styles of the LASER DIODE CONTROL
BOARD. The BOARD contains a silk-screened Canon
Part No. with the last two digits:
1. -02
2. -03
3. -07
Note
Versions -02 and -03 are identical in the adjustment and
will be referenced as -02/-03 BOARD. Version -07 is
referenced as -07 BOARD.
[1] De-energize the LASER PRINTER.
[2] Remove the TOP COVER.
[3] Loosen the 5 SCREWS and remove the LASER
DIODE CONTROL BOARD COVER.
[4] Connect 1 PROBE TL-2074 to the Channel A
input of the OSCILLOSCOPE TL-3348.
[5] Connect the other PROBE TL-2074 to Channel B
input of the OSCILLOSCOPE TL-3348.
[6] Set the time base to 50 nsec or .05
µ
sec.
[7] Set the voltage levels for each channel to 50 m V/
div.
[8] Set the trigger to Channel A, +slope.
[9] Set the LASER DIODE CONTROL BOARD
SWITCHES to the following:
-02/-03
-07
SW1: 3
SW2: 3
SW2: 3
SW3: 3
SW3: 3
DSW1: F
DSW2: F
DSW3: F
H129_0015AC
COVER
BOARD
CONTROL
LASER DIODE
SCREW(5)
H129_0015ACA
