Canon GP335 Service Manual page 496

CHAPTER 14 TROUBLESHOOTING
17 E220 (The scanning lamp turned on in error.)
18 E301 (The scanning lamp intensity is faulty.)
Cause
Scanning lamp
Connector
Connector, Sensor
Flat cable
connector
Intensity sensor,
Harness
DC controller
PBC
Composite power
supply PCB
Harness
CCD unit
Image processor
PCB
14-78
Step
1 • Does the scanning lamp turn on
when the Copy Start key is
pressed?
• Execute FUNCTION>MISC-
S>SCANLAMP in service
mode. Does the lamp turn on?
2 Are both ends of the scanning lamp
blackened?
3 Is the connection of J706 on the
image processor PCB normal?
4 Check the wiring between the
intensity sensor and the DC
controller PCB; then, clean the
intensity sensor. Is the problem
corrected?
5 Is the lock on the flat cable
connector (J706) on the image
processor PCB engaged?
6 Is there an output of about 0.2 to
0.5 VDC at J112-A5 on the DC
controller PCB when the lamp
turns on?
7 Is there conductivity on the harness
between the intensity sensor and
the DC controller PCB?
8 Is there electrical continuity
between J103-A9 and J113-B12 on
the DC controller PCB?
9 Does the voltage at J113-B12
(change from about 2 to 3 and then
to about 1 VDC when the lamp
turns on?
10 Is there continuity of the SYNC
signal between the CCD PCB and
the IP PCB?
• J705-39 and J301-2
• J705-37 and J301-4
11 Replace the CCD unit. Is the
problem corrected?
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Check Yes/No Action
NO See "The scanning lamp
fail to turn on."
YES Replace the scanning
lamp.
YES Correct the connection.
YES End.
NO Lock the connector.
YES Go to step 8.
NO Go to step 7.
Replace the intensity
YES
sensor.
NO Replace the harness.
NO Replace the DC
controller PCB.
NO Replace the composite
power supply PCB.
NO Replace the harness.
YES End.
NO Replace the image
processor PCB.