2 Apr
2019
2 Apr
'19
1:47 p.m.
Grant,
I miss my 4M+ with duplexer and extra paper tray. :-(
Yes, these guys were built like tanks. This one acts as a 4M now because I added the PS
module to it and it has local talk support. No duplexer or extra paper tray though :(.
I've found that the age of the paper isn't as
important as any dust
accumulated on the top sheet.
I will have to keep that in mind. This paper was old - not sure how old but it was in the
tray when I found the printer on the side of the road. So better to recycle it then risk
it I think.
I thought that there was a temperature sensor to
detect how hot the
fuser is and error if it's not warm enough.
It may be "hot enough". They are certainly warm. And I don't detect them
getting any hotter to touch as more printing goes on so this part could all be in my
head.
I can't sign in to look at the picture. If I can,
I'll look at it
later.
I can post it elsewhere if needed. It basically shows the picture getting darker with
subsequent printings.
How dark is the image that's being transferred to
the drum?
I am not sure how to quantify it but it looks solid on the drum. I will
have to repeat the test with a "cool" printer and see if it still looks solid or
not.
If the normal image is being transferred and toner is
being consumed, I
would wonder where the toner is going.
Never thought about it but the extra toner (I assume not all the toner is being
transferred to every page of print) must get swept up back in to the cartridge somewhere,
no?
How clean / dirty is the fuser cleaning pad?
Not too bad. It is worth mentioning that the printer doesn't seem abused in its old
life either. Only 65K of prints...
The things that come to mind are shifting High Voltage
(?) and
temperature.
Both of which should produce an error usually...
The other thing that comes to mind is possibly toner caked up in the
toner cartridge.
I thought about bad toner but that doesn't explain the improvement with time/prints.
Or why it would go bad again after cooling down.
How long can you wait after getting a good printout before they start
to
fade again? (Assuming the printer stays on.)
I would say 5 - 10 minutes. Once I get good quality prints the subsequent pages all look
great...
I'll share your email with a friend who was a
certified HP LaserJet
repairman. (I just pretended to be one a couple of jobs ago).
...
My friend replied with the following:
"""
- Bad / dirty contacts to the hi voltage
- Bad high voltage
- Bad DC power supply.
--
Thanks that was quick! I am pulling out the HV portion now to take a look. If I understand
correct the DC (LV) supplies everything else except the engine. Those all seem to be
working fine. Cleaning contacts is easy (and cheap) so that will be my first fix unless I
see something glaringly obvious with the caps on the HV.
Thank you.
-Ali