C253 Black Copies and Print Outs

[KMNewbie]

I have a brand new C253 with about 800 copies on it and all copies or print outs come out jet black with the image in the background......KM is lost in a closet, no help what so ever, so has anyone seen this.....(PRCB, HV Board and Image Processor has been swapped with new boards per KM instruction) Also, is there any tricks to reading bias, grid voltages, etc.... on this model ?

[ck1]

me got one C250 also got this problem . i will try change the black IU and see. let you konw A.S.A.P

[KMNewbie]

Tried a couple of different new drums also, still no-go......Thanks for your help !

[B0265]

Try swapping the Black laser unit with one of the others.

[copytechman]

I agree, try the print head swap, but also check to make sure the top of the drum/image unit is touching/connecting to the frame solidly, flaky grounds can produce a similar symtom as well.. I know you've changed an iu or 2 but also check the others for arcing @ the rear side contacts.. had it happen as well.
Regards!
A.

[Benedict]

Hi guy

Had a similar problem did everything under sun but after lengthy investigation found machine slightly bent on the left hand side maybe just something to take a look and look closely.

[ni311]

You can see the voltages in the service mode.
Is the black background on non-printable area also?