Poor c/q Canon image runner advance 7055

[copier wizard]

On running up this m/c it has been suffering from washed out image with black bands that move that seems to just go away and then return.This only occurs on black, single colours are ok.Drum heater has been turned on but still suspecting something to do with heater.
Please can anyone advise if you have experienced the same prob with this range of m/c's.
Thanks.

[copier wizard]

Sorry, thread seems to have been placed in Konica threads by mistake.