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

Ali cctalk at
Tue Apr 2 19:28:41 CDT 2019

Hello Guy,

> Or the drum isn't getting charged in the first place, before light
> exposure then toner dusting.
> A way to check this: while the machine is in mid-copy, cut the power
> then open it up and look at the drum.
> Is there a toner image adhered to the drum section between where the
> surface is image-exposed then dusted, and where it rolls against the
> paper?

As I alluded to in my OP I did do this test. When I looked at the drum after
I start getting normal prints there is an image. However, at Grant's
suggestion I also looked at it when the printer was first turned on. At this
point there is very minimal toner adhering to the drum. As I print more and
more an appropriate amount of toner seems to adhere to the drum explaining
the improving picture. What I am trying to determine is now if this is a
problem with a component in the cartridge (drum, corona wire, etc.) or is it
with the HV supply board.

> Btw, if the fuser roller isn't heated enough, the symptom is that the
> paper comes out with a normal image, except
> the toner wipes off with finger swipe. Since it's just sitting on the
> paper not stuck to it.

It is definitely not doing that. The toner is stuck on nice and tight - once
it eventually gets there.

> Old toner cartridges should be given a strong end-to-end shaking before
> being put into use. Toner can settle in
> lumps and block the path to the duster.

I have done this multiple times. However, the problem reappears.

> While you have the machine apart, always clean all the optical path
> lens surfaces. Dust greatly reduces the print contrast. And because
> most machines use fan-blown air, dust gets everywhere that isn't
> absolutely airtight sealed.

I have done that as well. However, given that the quality improves with
repeated printing and then falls back to none after 5 to 10 minutes of
cooling I don't think dust is an issue.

> One other tip that might be useful. Very commonly with old photocopiers
> and laser printers the rubber pick-up and paper feed rollers lose their
> 'tack' and slip on the paper.  I found that briefly soaking them in
> teatree oil restores the 'tack' quite well. It soaks in and seems to
> have the right spread of rubber-soluble oils to keep the surface a
> little tacky.
> Anyone else found other solvent/oils with similar effect?

I have never tried the oil/solvent trick. However, I did replace all the
rollers on this printer due to a paper jam issue so I don't think that is
the problem.

Thanks for the input and the suggestions.


More information about the cctech mailing list