Vertical white lines through your printed documents can be fixed by shaking the cartridge from side to side or replacing the cartridge. This problem is usually caused by the toner in the cartridge being clogged. Shaking the cartridge from side to side could dislodge the clog, restoring the print quality. If shaking doesn't help, you may need to replace the toner cartridge.
a) Replace the toner cartridge.
c) Shake the toner cartridge from side to side.
b) Use different paper. - Using the wrong type of paper can cause print problems, but not vertical white lines through the printed area. This usually results in incomplete characters, creased pages, and warped, overprinted, or poorly formed characters.
d) Replace the transfer corona. - A failed transfer corona will result in a blank page being printed.