HP Laserjet 4000T

[REA3600]

I did the maintenance kit for my printer and it solved some problems, but I still have a black line about 1" in on the left side of every page (vertical). What can I do to eliminate this line?
(My toner is about 7 months old - could it be old toner?)

[MichaelTech]

there may be some debris on the transfer roller, or in the fuser. If new fuser, check the transfer roller cavity for any toner. If a third party toner, it is probably the culprit.

[redcow]

Open the toner cartridge flap and look at the drum.