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

[Jon Elson]

On 04/02/2019 02:56 PM, Ali via cctalk wrote:
> 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.).
>
>
Is the fuser roller warming up properly?  Or, is it the 
corona supply is having trouble coming up to voltage?  You 
should pull the bottom of the printer apart and thoroughly 
clean the PC board on both sides.  If you have never done 
this, it will be a HUGE BLACK MESS with spilled toner dust - 
don't ask how I know this!

I have a 5M, but I think the mechanism is the same.

Jon