H/P LaserJet III "50 ERROR" After printing 3 pages

[Mark & Mary Ann Weiss]

I'm servicing a H/P LaserJet III laser printer that exhibits a '50 ERROR'
after running for a while.

I think the problem might be a temperature sensitive IC on the DC Controller
board, because the fuser assembly IS heating up at startup. The printer will
even print out a Font Test and do about 3-4 pages before the 50 ERROR
appears.

Once the error occurs, opening and closing the printer will not result in
the drive assembly rotating the rollers 1/4 turn as is usual for a normal
working LJ-III. This further suggests that it's a DC controller issue.

The question is which IC is most likely the problem. Anyone have experience
with this printer from a factory service angle that has seen a statistical
failure of certain ICs?

--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
Business sites at:
www.dv-clips.com
www.mwcomms.com
www.adventuresinanimemusic.com
-

 

[Nelson]

I'm servicing a H/P LaserJet III laser printer that exhibits a '50 ERROR'
after running for a while.

I think the problem might be a temperature sensitive IC on the DC Controller
board, because the fuser assembly IS heating up at startup. The printer will
even print out a Font Test and do about 3-4 pages before the 50 ERROR
appears.

Once the error occurs, opening and closing the printer will not result in
the drive assembly rotating the rollers 1/4 turn as is usual for a normal
working LJ-III. This further suggests that it's a DC controller issue.

The question is which IC is most likely the problem. Anyone have experience
with this printer from a factory service angle that has seen a statistical
failure of certain ICs?

--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
Business sites at:
www.dv-clips.com
www.mwcomms.com
www.adventuresinanimemusic.com
-

You might try http://www.fixyourownprinter.com. I found the guy very
knowledgeable and helpful.

 

[Allodoxaphobia]

I'm servicing a H/P LaserJet III laser printer that exhibits a '50 ERROR'
after running for a while.

Post here, too:

comp.periphs.printers
comp.sys.hp.hardware

Jonesy

 

[Jeff Liebermann]

I'm servicing a H/P LaserJet III laser printer that exhibits a '50 ERROR'
after running for a while.

My guess(tm) is that it's the power block. That directly under the
upper fan in the back right corner.
http://www.all-laser.com/error50.html#hp1
The delayed failure implies that something is getting hot when
printing. My guess(tm) is that one of the electrolytic cazapitors in
the power supply (there are two boards) is leaking or dying. There
are about 4 or 5 small green electrolytics on one of the boards that
my ESR tester often shows as gone. I replace them all.

 

[James Sweet]

I'm servicing a H/P LaserJet III laser printer that exhibits a '50 ERROR'
after running for a while.

I think the problem might be a temperature sensitive IC on the DC Controller
board, because the fuser assembly IS heating up at startup. The printer will
even print out a Font Test and do about 3-4 pages before the 50 ERROR
appears.

Once the error occurs, opening and closing the printer will not result in
the drive assembly rotating the rollers 1/4 turn as is usual for a normal
working LJ-III. This further suggests that it's a DC controller issue.

The question is which IC is most likely the problem. Anyone have experience
with this printer from a factory service angle that has seen a statistical
failure of certain ICs?

I fixed a few Laserjet II printers a couple years ago, they each had a bad
electrolytic capacitor on the board by the power supply.

 

[Mark & Mary Ann Weiss]

I fixed a few Laserjet II printers a couple years ago, they each had a bad
electrolytic capacitor on the board by the power supply.

Thanks for the input, everyone.

I hadn't thought of the capacitors before. These are on the AC controller,
right?

Most of the input I've gotten was that the AC controller (the board under
the fan) was 90% the likely culprit.


I did a little experiment today, which is still inconclusive:

Apply heat to the DC controller board. Turn the printer back upright. Power
up, wait for self test, request fonts printout. It never made it that far.
If I don't heat up the DC controller, I usually get 3-4 pages out of the
printer before it displays '50'. I'll have to repeat the test a couple of
times to see if it's repeatable. Then I'll try the same thing with the AC
power module.


--
Take care,

Mark & Mary Ann Weiss

VIDEO PRODUCTION . FILM SCANNING . AUDIO RESTORATION
Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm
Business sites at:
www.dv-clips.com
www.mwcomms.com
www.adventuresinanimemusic.com
-

 

[joe devlin]

A 50 error is the fuser overheating. It could be the fuser itself or
the AC power module.