dirty black background

[northeastprinter]

I am using a CL7000 which appears to be 'snowing' black toner. The whole sheet is suffering from a dirty grey image, edge to edge in both directions. I have changed the PCU, I have cleaned everything I can think of, but still it won't go away. Just to compound the issue, the first few sheets out are clean !!

Any ideas or suggestions would be greatly appreciated.

[CableGuy]

What is the life on the black dev counter?

[northeastprinter]

Dev Counter

I can't be sure because the counters have been reset from time to time, but it is likely to be high. I will change the unit and check results.

Thanks for that Cableguy

[scepter2112]

Never ran across this problem with this model, however it sounds like a ground problem. First few copy's clean then background.