My HP laserjet 1012 printer prints many dark vertical lines on pages when i print anything. The lines are about 1.5 inches apart. THe lines reprint the part in the document before it. THere are lines even when i try to print a blank page. THis is very annoying. CAn anybody please help me?
Its been 10 years since I used to repair laserjets, but normally there were 2 causes of vertical lines, either a bad toner cartridge or a bad fuser. On the older LJ2/LJ3/LJ4 you could take out the toner cartridge and slide back the window and look at the roll inside. If you see the streak on it, then try replacing the toner cartridge. A fuser is fairly easy to replace, at least on the older models I have worked on, though you should probably take that to a shop to have it done. Another possiblity is the primary charging roller, especially since you mentioned that parts of the previous document shows in the lines. A laser printer works by charging the paper with a negative charge and the toner with a positive charge (or vise versa, I forget) When the paper goes through the magnetic properties of the different charges make the toner go to the paper. It sounds like all of the toner isn't doing that since you are still seeing remnants of the previous document. If you had said horizontal stripes then that was usually a bad DC controller or a bad Scanning Assembly. First thing I would try is a different toner cartridge, if that doesn't do it then more than likely you need to take it in for service since there are a few possibilities of problems and it would be hard to determine which one to fix by yourself.
