Canon 8500

[dqtek]

Blank Copies

[wz7ntn]

blank copies

This issue on this copier (IR 8500) can be cause by several components.

Firts, check the wiring corona on transfer and primary
second, check the UR, probably its disconected or something
thirt, could be a problem with the drum

Probably you need to specify in whitch conditions its the blank copies...


regards

MH

[dqtek]

The Coronas are coming on. Replaced Lazer, drum unit, Copier can scan to PDF. There is just no Image on paper.

[montana]

what about the developing assembly is it in correct position...check the bias contact

[wz7ntn]

check also the coronas contacts back inside the copiers.. sometimes those contacts get broken..

regards,

MH

[teckat]

Blank Copies

Old PUB Below




imageRUNNER 85 / 85+ / 105 / 105+ / 7200 / 8070 / 8500 / 9070 Blank Copies

The machine is producing blank copies, after performing maintenance to the AP kit. The following were checked and are in order.
*VL1M and VDM were within target values.
*10K ohms of resistance measured from the hvt to the end of the developing cylinder.
*DEV_DC CNTR signal was present from the DC controller J510-A9 to the hvt at J723-8.

After further investigation, it was found, there was no developer bias present at the end of the mag roller(1), when checked with a multi meter. With the bypass door open, interlocks cheated and the developer pulled slightly away from the drum, the bias would return.






In this instance, the potential control sensor was taken out during servicing and cleaned. When the sensor was installed back into the machine, it wasn't seated correctly. This caused the mount (2) to touch the developer and short the bias to ground; resulting in blank copies. After setting the potential control sensor in the correct position, the copies returned to normal.

[teckat]

Blank Copies

OLD PUB BELOW>>>>



imageRUNNER 105 / 8500 / 7200 Blank copies

Unit will operate normally with no error codes, but will not produce an image on the paper when printing, copying or internal test prints.


To correct this issue use the following steps.
1.Begin by entering service mode Copier>Display>DPOT. Compare your VDL1-M reading to your VDM-M. If VDL1-M is the same as VDM-M then proceed to the next step
2. Using the laser power checker (part number FY9-4008-000) verify that the laser power is within Canon specs for your specific machine.
3.If the laser is in proper specification, then the laser may not be aligned properly to allow it to write to the drum's surface. This can be caused by the laser mirror being out of postion.
To access the laser mirror it is neccessary to remove the following parts:
1. Feeder
2. All top and back covers
3. Control panel
4. Reader controller PCB
5. Laser assembly
6. Developer
7. Drum unit
8. CCD PCB
9. Lens mount assembly (found on page 210-1 of the parts catalog). The lens mount assembly is held down by four shoulder screws in the corners. Once removed, the Lens Mount assembly will come out as one piece (Do not bend or drop the Lens mount assembly). It is not necessary to remove motors or the mirror assembly. Simply disconnect the wiring from the main body up to the lens mount assembly .
The laser mirror is pictured in the diagram (seebelow) between part numbers 25 and 32. There is no part identifier number or part number for the laser mirror. DO NOT adjust any of the mirror adjusting screws on the laser mirror. If the mirror is out of position, very carefully reseat the holding clamps and verfiy the shims on the back side of the mirror are in their proper position. The shims aligin vertically to the edges of the laser mirror. Once the mirror is seated correctly reassemble the unit and check to verify that VDL1-M and VDM-M meet their target value. (note the values in the DPOT will not change until after the unit performs inital rotation and performs potential measurement).

Canon USA, Inc. S

[SCREWTAPE]

Have you checked potential control.

Also make sure your developing bias connector is seated well.

The laser scanner unit has been known to cause issues like this.

Here's some info.