Lexmark optra c710 printer problems 1

[wabstowcross]

Can anyone help me sort out a problem I am having with my C710 colour laser?
When I print solid colour including black there is a vertical line where the colour is far less intense about 2mm across.

I have replaced all the colour cartridges and the transfer belt. The problem is still there.
Many thanks

 

[micker377]

Does this occur on a printer "self-test" (unplugged from computer), also? This would seperate a software problem from a "dirty" roller problem. They do make a cleaning kit for this.

 

[wabstowcross]

Many thanks for the suggestion. I have used the test manus to check the printing to confirm it is not the software. I will check all the rollers next.
Dave