Not DEC related but still hoping for some help: Problems w/ LJ 4+ Printer

[Alexandre Souza]

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.

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http://www.tabajara-labs.blogspot.com
http://www.tabalabs.com.br
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Em ter, 2 de abr de 2019 às 16:56, Ali via cctalk <cctalk at classiccmp.org>
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
>
>
>
>