Knowledgebase

Laser Printer Halfway Test

The halfway test is a handy way to isolate print image defects. To perform the test, print a page and then stop the paper halfway through the printer by opening the lid. This works best if you print from the manual or MP tray, because you can see the paper go into the printer.  Open the printer lid just as the trailing edge of the page disappears into the printer. Now remove the toner cartridge. Ideally, the page will be stopped between the cartridge and fuser, with part of the image on the page (but not fused), and part of it still on the drum (in the toner cartridge).  Observing these two partial images can help you decide where the defect is originating. There are three possibilities:

•   There is no visible defect in either partial image. Assuming the defect is not sporadic and happens on every  printed page, this eliminates everything before the fuser.  Therefore, the defect must be originating in the fuser.

•  The defect is visible on the paper but not on the drum.  This  eliminates logic boards, laser/scanner, toner cartridge, and fuser. Either it is a transfer issue (bad transfer roller or high voltage) or a mechanical issue (rubbing or vibration in the area between transfer and fuser).

•  The defect is visible in both partial images.  This eliminates transfer and fuser.  The defect originates in the toner cartridge, high voltage, laser/scanner, or logic boards.  Additional troubleshooting may be necessary to distinguish between these possibilities.