We have a customer that is having very light copies or prints in color and black. It was doing this when we got the call for transfer roller, ozone filter and color image units. After installing these parts the quality is no better. The transfer roller has a clip (grounding?) behind it that was bent in and had chewed a strip out of the roller, I thought that might be the problem but the new roller didn't fix the problem. I tried adjusting 2nd transfer and a few other adjustments but they had no effect. I stopped a test print before it got on the paper and the image on the transfer belt seemed to be good. The customer said that the copies just started getting lighter gradually. Is it possible that the clip damaged the transfer roller power supply? It does seem like a transfer problem. The image looks like there is an extreme amount of moisture in the paper but good paper and printing on both sides make no difference. The machine has 467K on it. Thanks in advance for any suggestions.

I would try swapping the transfer belt. See i it makes a difference. at the very least you will eliminate the belt as a possible cause.

If the roller was damaged, it may have damaged the transfer belt.

If you haven done so already I would clean print heads and run gradiation adj and then stablization ...

We have had the same problem, and as you suspected the High Voltage Unit was damaged.

Thanks all. It was HV-1 High Voltage Unit.