C451 ghost image

**bsm2** · 07-11-2010

looks like laser, image shifted 1 inch to the top of page
Does not appear to be a cleaning problem, happens on one copy, print, internal, and off the glass lead edge is on the left side of sample

**Stirton.M** · 07-11-2010

A few things to check....

Check the transfer belt autoclean is set in tech rep. You can also bump up the values for the positive and negative in relation to the cleaning process. Don't go overboard with this setting, it can be stressful on the HV components.

Also, check the fuser unit. Is it a new unit or an old one? If it is a new unit and the previous one did not produce this problem, likely there is a problem with the new unit. Swap out to check. Even using an old one that you know is relatively ok should be enough to check. If the existing fuser is an old one, check the teflon on the heat side is ok.

You can also bump up the fuser temperature on the press and heat rollers.

And this is a bit of a pet peeve of mine, and a few others here, but if you already have a thread going on this, keep using that thread and simply bump it up if it falls off the first page unresolved.

**bsm2** · 07-11-2010

Does not appear to be a cleaning problem, happens on one copy, print, internal, and off the glass lead edge is on the left side of sample

replaced fuser, 2nd transfer imaged shifted

**Stirton.M** · 07-11-2010

If it is just a single print and that is what is happening, then I would venture to say you may have an image processing issue. I am assuming the print is short edge at the bottom is lead edge? Or the top is lead edge? I zoomed the sample and it appears that this is less ghosting and more electronic. The latent image looks a bit stretched and broken up into line segments.

In the case of image processing, it may be quite difficult to trace, you can try swapping the RAM on the PRCB. Replace the image processing board as a starting point. I would say do all the boards one at a time, but if you haven't a spare machine to do this, it isn't practical, as this will be a huge hit to your parts budget if none of the boards corrects the issue. It may be even something simple like a grounding issue on the laser unit, or a poor electrical connection on the control board or harness bridges.

**bsm2** · 07-11-2010

lead edge is left side of image trail right side , agree image processing issue looks like one of the mirrors on the polygon motors may have shifted? machine also has a P-14 error

**Stirton.M** · 07-11-2010

Ok, then that certainly isn't a latent image in the transfer areas.

It could very well be related to the laser unit, though I doubt it would be one of the mirrors on the polygon motor, the polygon is one solid piece. It would seem that noise is being introduced someplace or there is a defective component as I mentioned earlier.

And though I doubt it is this problem, one troubleshooting recommendation related to blurred reproduction in the manual mentions cleaning the print head window, something may be deflecting a part of the laser light. At the very least, cleaning that can't hurt and it will eliminate that possibility. Beyond that, I am at a loss as to a direct cause, aside from doing the swapping of components.

**mo0651** · 07-12-2010

It looks like only black is repeating. and quickly within 1.5 inches? Do some single color copy and see if it is only black. How many copies on the black drum?