If I'm not mistaken, high voltage capacitors on power supply. The corona wire isn't charging the paper, so the image doesn't get transfered from the cylinder to the paper to be pressed/fused in the fusor.
---8<---Corte aqui---8<--- http://www.tabajara-labs.blogspot.com http://www.tabalabs.com.br ---8<---Corte aqui---8<--- Em ter, 2 de abr de 2019 às 16:56, Ali via cctalk <[email protected]> escreveu: > I rescued a LaserJet 4+ printer that I have been trying to restore. > Initially everything seemed ok and it seemed as if there may be just a bit > of an issue with paper pickup which I attributed to old paper in the tray. > > However, soon I started getting the accordion paper jam which led me to > replacing all the rollers including the transfer roller. Now the paper > flows > freely! However, I am having a new problem with printing. When I print, the > first 5-10 pages initially come out blank. The printer does not produce any > errors or error codes. The blank pages are warm (not hot though) as > expected > out of a LJ. > > After closer inspection it seems that the pages are printed SUPER light and > gradually get darker the more I use the printer continuously. Eventually > the > printer starts printing continuous crisp black pages like new. This is a > whole page phenomenon (i.e. not gaps, missing areas, etc.). > > A picture of the effect can be seen on VFC at: > www.vcfed.org/forum/attachment.php?attachmentid=52120&d=1554074105 > > Sorry for the poor quality picture. > > Things I have checked/tried: > > 1. Using a brand new NOS toner (according to HP toner does not go bad as > long as it was sealed - which this was) > 2. Swapping the new transfer roller for the old one - same problem, I have > to print out a bunch of pages until the printer starts acting normally. > 3. I have checked the HV and an image is being transferred to the drum on > the toner cartridge. > 4. A visual inspection of the fuser shows it to be ok. > > Obviously this is happening printing demo pages so it has nothing to do > with > computer, OS, SW, drivers, etc. Anybody run into this before? Any > ideas/suggestions. My Google fu turned up a bunch of discussions on the > laser door not being aligned correctly but that would seem to be a more > permanent issue i.e. unless you fixed the door no pages should print ever. > Mine gets better on its own after a number of pages are printed. Plus the > door and spring are fine - I checked them just in case. > > I tried posting on FixYourOwnPrinter.com but for whatever reason the site > was not accepting the question. Any other forums you guys would recommend? > TIA! > > -Ali > > > >
