Canon GP215 Service Manual page 300

3. OPERATIONS AND TIMING
13) Select either 'MULTI', 'CASSETTE1', or 'CAS-
SETTE2'.
(Press the appropriate item to select so that
the cursor (
14) Generate a PD pattern print. (Press 'PD PRINT'
to highlight; then, press the Copy Start key.
• You will be using the pattern print later.
15) Place five to ten sheets of blank copy paper
on the copy board, and close the feeder or the
copyboard cover.
Copy paper
Figure 3-1012
16) Press 'WHIE MEASURE' on the screen to
highlight, and press the OK key.
• The scanner will move forward to read the
blank copy paper.
17) Remove the blank copy paper from the copy-
board glass, and place the generated pattern
print on the copyboard glass against the V
marking at the rear left.
(You must place the pattern print correctly, or
correct adjustment will not be possible.)
Place the pattern print as shown
When the pattern print is placed reversing (left/right)
its orientation, the image becomes appreciably light.
Printed side down
Figure 3-1013
3–246
COPYRIGHT © 1996 CANON INC.
) points to the item.)
Copyboard glass
18) Press 'DENSITY SAMPLING' to highlight;
then, press the OK key.
• The scanner makes 13 scans.
19) At the end of the operation, check to make
sure that the values under A, B, and D on the
LCD are as follows.
If the values are not as shown, start over at step
7) since the adjustment may have been wrong.
Reference:
A, B, and D are approximate values so that
optimum images may still be obtained even
if the values are outside the range; you may
omit "temporary remedy" as long as the
images are optimum.
For PD and 200PWM
20 ≤ A ≤ 50
-40 ≤ B ≤ 40
0 ≤ D ≤ 8
For 600PWM
20 ≤ A ≤ 60
-70 ≤ B ≤ 20
0 ≤ D ≤ 8
20) Check the above, and press 'DATA SET' to
highlight; then, press the OK key.
• This will set the values under A, B, and D
which have been measured.
21) Press the Page key, and execute '200PWM
density auto adjustment'.
(Follow the same steps starting with step 9) to
execute the mode.)
22) When '200PWM density auto adjustment' is over,
execute '600PWM density auto adjustment'.
(Follow the same steps starting with step 9) to
execute the mode.)
23) Press the Reset key twice to end service mode.
If the values under A, B, and D are not as indi-
cated after executing 'copy density auto correc-
tion' several times and, in addition, optimum
images cannot be obtained, you may perform the
following as a "temporary remedy":
The temporary remedy will enable normal copy-
ing; however, since the image quality will lower, be
sure to correct any fault as soon as possible, and
execute 'copy density auto correction' once again.
Possible Faults
• Drum unit
• Scanning lamp
• Laser unit
• Composite power supply PCB
• Analog processor PCB
• Image processor PCB
CANON GP215/200 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)