A thick black line is on the right side of all printouts from an older Brother MFP. Users say they tried to use the manual slide to clean the unit but it made the line thicker.
What are the chances that the problem is with the internal components, and not with the drum which is due to be replaced? Is there a way to test the unit to know whether to replace the drum, or replace the MFP?
I will blow out the internals in case any toner has accumulated, but it does not look like that is the issue. If the issue is part of the cleaning stage of the laser print cycle, that would be fixed by replacing the drum, yes? The problem started a while ago and I was not notified, and the toner is currently very low.