Canon NP6621, Service Handbook, Page: 35 / 146

2–21
STANDARDS AND ADJUSTMENTS
6 Initializing the Back-Up RAM
1) Open the front door, and insert the door switch
actuator into the door switch.
2) Press the service mode switch (SW850) with a
hex key.
• The machine starts service mode and indi-
cates ‘1’.
3) Press ‘4’ on the numeric keypad.
• The display indicates ‘4’.
4) Press the AE key.
• The machine starts operation/inspection
mode and indicates ‘401’.
5) Press ‘5’ and ‘0’ on the numeric keypad.
• The display indicates ‘450’.
6) Press the Start key.
• The display changes to ‘EE’.
8) Press the Start key.
• The display returns to ‘EE’.
9) Turn OFF/ON the power switch.
• The back-up RAM is initialized and set to
default settings.
Reference:
To stop initializing the RAM, press the Clear key
and then the Reset key.
To stop it after performing step 8), press the
start key, and press the Start key after the
display has indicated ‘nop’.
7 Checking the Photointerrupters
The machine’s photointerrupters may be
checked using a conventional meter or in service
mode.
q
Using a Meter
1) Set the meter to the 12VDC range.
2) Connect the - probe of the tester to J301-4
(GND) of the DC controller.
3) Make checks as indicated.
1: 5 V
0: 0 V
w
Using Service Mode
1) Open the front door, and insert the door
switch actuator into the door switch.
2) Press the service mode switch (SW850)
with a hex key.
3) Press ‘2’ on the numeric keypad.
• The display indicates ‘2’.
4) Press the AE key.
• The machine enters I/O display mode
and indicates ‘201’.
5) Enter the appropriate number using the
numeric key, and press the Start key.
• Check each photointerrupter with refer-
ence to the copy count indicator.
Figure 2-241
2-a 1-a
2-f
2-b
2-g
2-e
2-c
2-d
1-f
1-g
1-b
1-e
1-d
1-c