C5501 variation side to side

[retro]

We are fighting a print shop C5501 that is varying as much as 2 -3 mm side to side (in the main scan direction). Lead to trail registration is fine. There is no skew. We did the centering adjustment for each tray,LU,manual bypass, etc. The tires were replaced for each feed station. The side to side registration will be perfect at the start of a single sided run sent from the network and gradually shift as much as 2 to 3 mm by the time copy number 100 is done. The machine total counter is only 200k.

Any suggestions or help is sure welcome

[Christian_W]

Hello retro,
there is a centering sensor in the LU. If the paper comes in a wrong postition to this sensor, he shit the image to the "right" position.
It is possible, that the sensor is defekt.
We often have this problem with the LU-202 if the side plates are not in the right position.
The sensor checks the side position of the feeded paper. The paper must pass the sensor at a defined postiton. If the side plates in the magazin are shifted to front or backside, the sensor becomes wrong input and the he sometimes start to shift the image.
Please loose the two screws on top of the side plates and try to set the paper in the middle position of the papertray.

Good luck
Christian

[retro]

Hi Christian

Does that affect the side to side registration for all of the paper trays and manual by pass? The machine is shifting the image for all paper trays and manual bypass, not just the LU paper deck.

Thanks for any info

[Christian_W]

Hello retro,
no, that affect is only at LU-202.
Is the image shift on the first or on the second side? In the ADU, is another centering sensor, but it is only for the second side.
I have no other idea about an image shift in main scan direction.

regards
Christian

[retro]

does it single sided from any paper input. The colors are not mis alligned and no skew.

The whole image is shifting over 1 to 3 mm in a hundred copy run of the same image. Starts out perfectly centered and the void areas on each side get smaller or larger depending on how far it shifts, usually to the right from what I have seen there.

Thanks for any info

[Christian_W]

Hello retro,

I think it is possible, that the Image Processing Board or the Printer Control Board is defekt.
The IPB get the signal from the centering sensor and starts to write the image in Main scan direction.
If we have image problems, often the PRCB is defekt.

[Stirton.M]

We simply just disable the sensors. Too much of a pain in the ass to screw around with every other day. Changing the sensors sometimes works, but not always.

Disable the sensors, software switch 26-4 and 25-5 (LU/PF and ADU respectively). By default, they are enabled (0). Disable them (1).

The drawback to this is of course, you need to manually adjust all the paper trays both physically and electronically to center. Start with the PF/LU unit, since those have zero mechanical adjustments. Then adjust trays 1-3 based on the ADU second side electronic adjustments made for the LU/PFU. Second side is unfortunately not configurable for individual trays.

Once done, we have had zero issues with front to back centering, and any fine adjustments can be done via "image shift" within the driver settings or from Command Workstation if you plan on duplexing anything that requires crop alignment.