C6500 image shift

[blago_vd]

Hello everybody,
I have a problem with C6500P , 900 000 clicks. When printing heavy stock from bypass image shifts occasionally up to 4 mm in main scanning direction. The image shift is not constant. I changed the transport rollers, but with no effect. Also checked the paper path in registration section. Any ideas?

[italo]

Re: C6500 image shift

Hello everybody,
I have a problem with C6500P , 900 000 clicks. When printing heavy stock from bypass image shifts occasionally up to 4 mm in main scanning direction. The image shift is not constant. I changed the transport rollers, but with no effect. Also checked the paper path in registration section. Any ideas?

clean all clutch, with alcohol isopropilic , you can use a paper aroun the 200gr with alcohol isopropilic,

[twinax]

Re: C6500 image shift

Hello Italo,

Is your problem on one side of duplex printing or also on single side?

Most of time this problem is caused by the CCD registration which is dusty (not clean), when bypass is used, it means that the problem is only on second side (CCD on duplex section).

Check all whites transport rollers from bypass to registration roller. this rollers need to be perfect.

Regards,

Twinax.

[dljorg]

Re: C6500 image shift

If the image is shifting intermittently about 5mm away from the operator problem is either in the centering sensors (one in LCT or PF unit and one in the duplexer) ... Diagnostic is to turn the centering sensors off with DIP 25-4 and 26-5 and run for a while - if no shift it was the sensor.

or

the back wall of the PF unit drawer has shifted. Wall shift happens when the drawer is closed too hard with the drawer full of paper. There is a procedure in the manual for putting the drawers back in time. What happens here is the centering sensor will work up to about 5mm. A one tooth jump in the wall centering gears is just short of that 5mm. Most of the time the sensor will work but every once in a while the page is just too far out and the sensor position correction gives up - bingo a 5mm jump.

The wall thing is pretty common.

[Haaland]

Re: C6500 image shift

It can also be the registration loop, if its adjusted to high the paper will be pushed past the registration roller before the rollers starts turning, causing the timing between the registration roller and belt to be wrong.