mike.august

asked May 24, 2017 at 10:19am
Hp HP LaserJet 4M

Black vertical streaks, smudged pages

I have an HP Laserjet 4m. After running a toner cartridge for 2 weeks, vertical streaks and smudges begin appearing on the pages. (At this point only remanufactured cartridges are available). Always, the waste toner section of the cartridge is filled, and emptying it and cleaning up gives good print for about another 2 weeks. (As in post 53359). After the second emptying, the cartridge only lasts a few days before it is empty. I have the print density set to 1 (out of 5). If the print density is set higher, the problem just occurs sooner. After a few times I have come to suspect that there is a problem with the voltage levels the printer supplies to the cartridge. Am I right? and what component should be replaced?

Bad drum wiper blade. https://fixyourownprinter.com/posts/76508

by moe on May 24, 2017 at 7:37pm Add comment

According to the EX service manual there is a rubber blade that "brushes" the toner on the developing cylinder to a uniform thickness inside the toner section. It would make sense that if this is worn, too much toner would be transported by the photoconductive drum. There is a second cleaning blade that wipes excess toner off the photoconductor after it applies the image to the paper. That toner ends up in the waste toner section. If that blade is worn, the toner remaining on the photoconductor would go back into the toner section and likely result in too much toner on the drum, and dirty images.

It is not clear from post 76508, which blade is the problem. However, it seems to me that a worn wiper blade in the toner section would be the first suspect cause of the problem and least likely to be replaced when refilling a cartridge. Can this blade be replaced without disassembling the toner section? And, are these available -- what should I search for?


by mike.august on May 30, 2017 at 9:59am Add comment