Canon IR2800 lead edge shading

[Guest]

I have a couple machines in the field that have shading on the lead edge about 1/8" wide from top to bottom 1st copy only and it's intermittent. i've replaced the drum, turned down the pri charge & dv charge. that has worked in the past but not on these machine's.
any ideas?

[SCREWTAPE]

Is this when you make copies or when you print.

[dcsbiker]

both copy and print

[SCREWTAPE]

This is a rather simple machine. Trying replacing the transfer roller. Check the developer. I would put back all original values back.

[dcsbiker]

Thanks
I haven't tried the transfer roller.