Startup System Failure Diagnosis; Overview - Canon imageRUNNER ADVANCE C255 Series Service Manual

Startup System Failure Diagnosis

Overview

The purpose of this diagnosis is to identify the cause when the host machine would not start up.
A combination of the following three identification methods is used to identify the cause.
• A method for identifying the failure on the basis of the LED/LCD display status
• A method for identifying the failure on the basis of the power supply/signal route
• Identification of the location of the controller-related failure with the controller self-diagnosis function
The diagnosis is made according to the startup system failure diagnosis flow in order to perform basic identification of the cause
and perform the remedy.
If it turned out that the failure was caused by the controller or the Power Supply Assembly, perform a controller self-diagnosis or
check the Power Supply Assembly, and perform the remedy.
If the diagnosis result shows that replacement of parts is required, perform the works in the order shown below.
1. Check if the connectors (of a cable, etc.) are connected properly.
2. Replace the cable.
3. Replace the parts.
After performing the works shown above, be sure to restart the host machine and check if the symptom occurs again.
WARNING:
When a tester is used to perform a check, the AC voltage may be measured. There is a possibility of electrical shock, so
caution is required during the work.
NOTE:
The numbers such as (1) and (2) shown in the flow diagram indicate that there is a check item table showing the items to be
checked in the flow chart, location, and procedure.
Each number in the flow diagram is linked with the item number of the corresponding check item table to be referenced.
the backlight gone off?
Is 12V supplied to J1001
of the Control Panel
CAUTION:
Before using a tester to perform a check, be sure to turn OFF the Environment Heater Switch.
If a check is performed with the Environment Heater Switch ON, the diagnosis may not be performed correctly.
NOTE:
When replacing the cable, disconnect the cable from the connector and check the continuity.
Flow
Start
Has only Yes
No
[Assumed failure location]
1. Control Panel Unit
(1)
2. Main Controller PCB1
Yes
CPU PCB?
[Assumed failure location]
No
1. Control Panel CPU PCB
(2)
2. Main Controller PCB1
3. Control Panel Unit
Check item list
The location of each check item
can be referenced by the
corresponding number in the flow
diagram.
335
6. Troubleshooting