Canon IR 8070 With Dark Background

[Guest]

Hi Friends,
I have a IR 8070 that makes a dark background after the first 10 or more copies. The first copies comes out clean but as you run more copies the background gets darker and darker. The machine has about 500k. Any help? Thanks.

[welshman]

dark copies

yes its the blank exposure lamps

check them or clean them

[Canuck]

No blanking lamps on digital..you mean pre-exposure..located on cleaner blade assembly...check the connector also where it plugs into ap assembly..wire broke or not plugged in..check lamps in service mode

[welshman]

opps

yes your right it was late when i wrote that had a hard day

but same applies it will be the pre exp lamps

[Copier_Guy]

Couldn't that problem also be caused by a failing Charge Corona Assembly?

[DadO]

I had similar problems on iR5570. Developing bias had fluctuations in voltage or discharge voltage problem not shure, but i cleaned all connectors of dev. ass. and plus I rewrite firmware, got my problem fixed.

[welshman]

failed charge assembly

nope

a failed charging assembly normally gives bark effect copier ie black down the edges intermitantly

never had one give clean then darker and darker copies

i would opt for the pre con lamps or conectors there easy to leave off on these orrible machines

[pons10]

main charge assembly

Thanks guys for your help. The main charge assembly took care of the problem.