Canon GP215 Service Handbook page 108

ARRANGEMENT AND FUNCTIONS OF ELECTRICAL PARTS
6. Protocol Controller PCB
J509
J1
a. Guide to the LED Indications on the
Protocol Controller PCB
Power-On
If all LEDs are ON, the power supply has
started normally.
About 10 Sec Later
If the 1st (LED0) from the right is OFF, a
memory check on the protocol controller PCB
has ended.
About 10 Sec Later
If the 2nd (LED1) from the right is OFF, com-
munication has started with the image proces-
sor PCB.
About 10 Sec Later
If the 3rd (LED2) is OFF, communication has
started with the Printer Board (an internal
check signal of the Printer Board has been
received).
About 10 Sec Later
If the 4th (LED3) is OFF, communication has
started with the NIB (an internal check signal
of the NIB has been received; remains ON if
the NIB is not installed).
b. Results of Self Diagnosis Indicated by
LEDs
LED0, LED1, LED2, and LED3 flash alternate-
ly in specific combinations.
6–22
J508
J201
J200
Figure 6-614
J505
LED2 LED0
LED3 LED1
c. Downloading
At time of downloading, the LEDs repeat
flashing starting with the rightmost LED.
J501
J506