Canon imageRUNNER ADVANCE 9070 PRO series Service Manual Digest page 70

E Detailed Occurance Items
code code area
E020 -0491 -05 Title
Description
of detection
Measures
3
E020 -04A0 -05 Title
Description
of detection
Measures
3-44
Description
Patch (Bk) density upper limit error
The ATR patch detection output (SigD) is more than 970.
• When the value of COPIER> DISPLAY> DENS>
P-LED-DA is large (153(D) or more) and the value of
P-SENS-P is small, there is a high possibility that dirt is
applied to the patch sensor.
• This occurs only at a regular timing. When the value
of COPIER> DISPLAY> DENS> DENS-S-x is small
(2 digits), there is a high possibility that breaking
occurred.
1. Check whether the developing assembly and the drum
unit are properly installed.
2. Clean the patch sensor.
3. Check the connection between the patch sensor and
the DC controller interface PCB. (Connector, Shorting)
Sensor side: J7412, J8035 PCB side: J1242
4. Check open/close operation of the patch shutter.
5. Check whether scratches/dirt are applied to the ITB.
If many scratches are found, replace the ITB. If dirt
is applied, clean the ITB. In this case, check the ITB
cleaning blade at the same time.
6. Replace the patch sensor unit.
NOTE:
This error also occurs when there is not enough toner in
the developing assembly. In this case, check the supply-
related parts in the developing assembly.
Toner density sensor (Bk) output lower limit error
The toner density sensor output (Vsig_ind) is less than
43.
1. Check the connection between the toner density sensor
and the DC controller interface PCB. (Connector,
Breaking (shorting))
<Y> sensor side: J7133, J8028, J8087 PCB side:
J1240, J8085
<M> sensor side: J7134, J8029, J8088 PCB side:
J1240, J8085
<C> sensor side: J7135, J8030, J8089 PCB side:
J1240, J8086
<Bk> sensor side: J7146, J8015, J8117 PCB side:
J1240, J8086
2. Check whether disconnection or shorting of the toner
density sensor occurs or not.
3. Replace the developing assembly.
E Detailed Occurance Items
code code area
E020 -04A2 -05 Title Toner density sensor (Bk) output upper limit error
Description The toner density sensor output (Vsig_ind) is less than
of detection 247.
Measures 1. Check the connection between the toner density sensor
and the DC controller interface PCB. (Connector,
Breaking (shorting))
<Y> sensor side: J7133, J8028, J8087 PCB side:
J1240, J8085
<M> sensor side: J7134, J8029, J8088 PCB side:
J1240, J8085
<C> sensor side: J7135, J8030, J8089 PCB side:
J1240, J8086
<Bk> sensor side: J7146, J8015, J8117 PCB side:
J1240, J8086
2. Check whether disconnection or shorting of the toner
density sensor occurs or not.
3. Replace the developing assembly.
E020 -04C2 -05 Title Patch (Y) sampling error
Description The variation before average patch P wave light intensity
of detection is more than 100.
Measures 1. Check whether the developing assembly and the drum
unit are properly installed.
2. Clean the patch sensor.
3. Check the connection between the patch sensor and
the DC controller interface PCB. (Connector, Breaking
(shorting))
Sensor side: J7412, J8035 PCB side: J1242
4. Clean or replace the ITB.
5. Replace the patch sensor unit.
6. Replace the developing assembly. (Check whether
there is not uneven coating on the developing sleeve.)
Description
• Check whether the ITB belt is dirty or not. If it
is dirty, perform cleaning with the service mode
(COPIER> FUNCTION> CLEANING> TBLT-
CLN).
• If it is assumed that this error occurred due to
scratches on the ITB, replace the ITB.
T-3-5