XEROX WORK CENTER 7755 BLACK SPOTS ON BLACK drum

[Dunu]

XEROX WORK CENTER 7755 BLACK SPOTS ON BLACK drum
I have some little spots over black drum of my XEROX WORK CENTER7755

[nicks]

Re: XEROX WORK CENTER 7755 BLACK SPOTS ON BLACK drum

I don't think that anyone is home here on the forum. I've been waiting for a response to my issue. I guess that we all win some and lose some.

[exCSER]

Re: XEROX WORK CENTER 7755 BLACK SPOTS ON BLACK drum

Hi Dunu,

I don't work on that particular model, but I've been servicing high-volume machines for about thirty years now, and that sounds like the kind of problem that would occur if the charge corotron were arcing, usually caused by bad wire or inadequate (high resistance) return.

Hope this helps.

Don

[Dunu]

Re: XEROX WORK CENTER 7755 BLACK SPOTS ON BLACK drum

Dear exCSER.
Thank so much for your reply, you have elevated my spirit.
I have this kind of machine family (Xerox dc 250 ) which I do service and maintain with the same problem. I tried all best , no result and I became frustrated .
Once again thank you.
Please further explain to me how to solve the BAD WIRE OR INADEQUATE (HIGH RESISTANCE) RETURN.
Thanks for your anticipating response.

Timothy Dunu

[exCSER]

Re: XEROX WORK CENTER 7755 BLACK SPOTS ON BLACK drum

Hi Timothy,

The charge corotron (offshore machines call this the corona) wire can develop hot spots that can cause the high voltage that goes through the wire to arc to the drum, damaging the surface in the manner that you described.
The charge that is applied to the drum has to have a return path to ground or the same type of arcing can occur. The machines that I have worked on that use a drum for the photoreceptor usually have a metal plate on the inboard side which makes contact with another plate inside the machine for its return. Sometimes these plates can become contaminated and do not make a sufficient electrical connection, increasing the resistance in the circuit.
Hope this helps!

Don

[Dunu]

Re: XEROX WORK CENTER 7755 BLACK SPOTS ON BLACK drum

Dear exCSER,

Thank you so much!

let me do as you said, I will feed you with the result.


Timothy Dunu