Light grey vertical line printing on left side of paper used the cleaning cycle and line in now doubled There is a black vertical line down left side of the page. I used the cleaning page but the line is still present and seems darker. Now what?

remove toner and drum unit
remove toner
check to see if there is toner in the drum unit if not fill unit run 5-10 prints
replace dev roller
replace drum cylinder(opc)

the two places to look is transfer roller and the fuser unnit.
i think there is a problem with the transfer roller it is under the toner and it needs to be spring loaded. The paper passes between the toner an the transfer roller to charge the paper en let the toner stick to the paper and if it doesn't make correct contact then it wont work

If you are seeing vertical streaks/black lines your primary corona wire is dirty and or the fax scanner may be dirty.
1)To clean the corona wire you take the drum unit and toner cartridge and place it on disposable paper to avoid spilling.
2) Clean the primary corona wire inside the drum unit by sliding the blue tab from right to left several times.
3) Return the blue tab and snap it into the home position.
4) Reinstall the drum unit and toner cartridge.
5) Close the front cover.
Caution: if you do not return the blue tab to the home position it may repeat the black lines.

...maybe its time to replace fuser fixing film!?

Clean the nozzles, align the print heads, turn it off for about an hour. You may need to do this twice, but it works for me.

Clean the small piece of glass on the flat bed. Should be on the left side of the flat bed when you lift the doc feeder.

It is a bad Toner Cartridge or Fuser. Most likey a bad toner cart.

Try rotating the page 180 degree it is in the advanced options. It worked for me on one system.

This is a workaround - I too need a definitive answer. Symptom: black dotted vertical line 1/2 to 3/4" from leftmost image edge. I have begun adding single vertical line to my prints .25" from the left edge of the paper to force the "dots" off my print - this seems to have the desired affect, but it does not answer the cause or provide a true remedy (it will save many of your prints while we wait for complete solution). dkh

Hi there check that it isn't the drum unit by turning the machine off open the top cover remove the toner and underneath you will have the dev unit unplug and lift out then remove the transfer tray (the one you open if there is a jam) open side door remove waste tank then you have the drum unit now to remove there is either a push button or a screw do either one that corresponds and check the unit. If there is a black line on one side the only way to get rid of the line is to replace the cleaning blade as this has worn. you can clean the drum unit cleaning blade it may only be toner stuck under the blade all you have to do is rotate the drum the opposite way of operation and if you have to hand a air line just give it a blast failing this it will defently need replacing.

Hope this is of some help
Please rate me
Cheers J