Adjustment Of The Media Sensor Light Intensity - Canon BJ-W7000 Service Manual

mm CHAPTER 5 TROUBLESHOOTING
11) Insert the cut sheet media into the printer.
* The printer feeds the media. The carriage
moves over the media, and the media illumi-
nation lamp lights.
Sensor Gain
[Adjust VR. Then
[Adjust VR. Then Press 1]
CAUTION
pe Use plain paper only. |
12) Set the tester to the volt range, and connect to
J412-3 (+) and J412-4(-) on the carriage PCB.
13) In this state, adjust VR202 on the engine con-
troller PCB so that the voltage across these
terminals is the value shown in Table 5-201.
Lamp intensity
at auto head
adjustment
vr | He | = | vottage |
VR202 | J412-3|J412-4 |16.5+0.1V
Table 5-201
14) Connect the tester to J412-2 (+) and
J412-4 (-).
15) In this state, adjust VR401 on the carriage PCB
so that the voltage across these terminals is the
value shown in Table 5-202.
Sensor
sensitivity at
auto head
adjustment
VR | + = Voltage
VR401 | J412-2 |J412-4|12.040.1V
Table 5-202
16) Press the down arrow key.
* The media illumination lamp goes out.
Sensor Gain
[Readjust Gain a
[Readjust Gain and Press | or Power Off]
17) Press the down arrow key again to light the
lamp.
18) Carry out the adjustment in step 13) to 15).
CAUTION
VR401 becomes stable after being ad-
justed two or three times. After the adjust-
ment, repeat steps 13) to 15) to check the
adjusted values.
19) Turn the- power switch OFF and remove the
media.
3. Adjustment of the Media Sensor
Light Intensity
This adjustment adjusts the lamp intensity of
the media sensor at media detection. Carry out this
adjustment after the engine controller PCB or the
following parts have been replaced:
* Carriage PCB
* DC power supply PCB
« Media sensor
This adjustment must also be carried out after
the carriage or platen has been removed.
CAUTION
Clean the media sensor and platen before
adjusting this adjustment.
During this adjustment, do not touch the
media sensor with your hands.
1) Remove all cartridges.
2) Set the cartridge height adjustment lever to the
right position (0).
3) Remove the expansion cover and right cover.
expansion cover
Figure 5-220
COPYRIGHT © 1998 CANON INC.