HP Laserjet 4 Plus error 50 Service?

[Bob Eager]

I have been given a Laserjet 4 Plus which, although old in years (4)
has seen little service.

Only it doesn't work! Gives a '50 SERVICE' error after the SELF TEST
and WARMING UP messages.

Can anyone point me in the direction of likely causes? Things I could
look at?

Thanks...

--
Bob Eager
rde at tavi.co.uk
PC Server 325; PS/2s 8595*3, 9595, 8550, 8570, 9556, 8580,
8557, 9556, 8550, 8530, P70, PC/AT..

[Alan Anderson]

50 error is a fuser problem error. Most likely the fuser lamp burnt out.
Remove the fuser by opening the back door, taking out two screws and
sliding the fuser out the back. Check continuity of the fuser lamp. (It
has white leads from each end.) If no continuity, that's your problem.

[Bob Eager]

On Sun, 25 Oct 1998 02:07:00, Alan Anderson <al...@fix.net> wrote:

> 50 error is a fuser problem error. Most likely the fuser lamp burnt out.
> Remove the fuser by opening the back door, taking out two screws and
> sliding the fuser out the back. Check continuity of the fuser lamp. (It
> has white leads from each end.) If no continuity, that's your problem.

Thanks. It turned out that the online manual had more detail than the
printed one in terms of error codes, and it too pointed to the fuser.

So, do I have to replace the whole unit? How does it come apart if
not? How much money am I looking at? This is a virtually new printer
except chronologically, so it might be worth resurrecting...in human
years, it's still at kindergarten!

[Wong Sy Ming]

Well, if you're determined enough, you can just replace the lamp by
disassembling the whole fuser (make sure it's the lamp....on a LJ3 the fuser
has countless screws...) and getting at the lamp.

Make sure it's NOT the lamp by poking a ohmmeter across the lamp ONLY
(after the thermoswitch). If the lamp tests OK, then test the thermoswitch.
If the thermoswitch tests OK then check the AC block.
Goto www.printerworks.com, they have complete exploded diagrams of
everything there.

Bob Eager wrote in message <176uZD2KcidF-pn2-dWVodYC8xVPo@rikki>...

[Bob Eager]

On Sun, 25 Oct 1998 15:21:50, "Wong Sy Ming" <sim...@singnet.com.sg>
wrote:

> Well, if you're determined enough, you can just replace the lamp by
> disassembling the whole fuser (make sure it's the lamp....on a LJ3 the fuser
> has countless screws...) and getting at the lamp.
>
> Make sure it's NOT the lamp by poking a ohmmeter across the lamp ONLY
> (after the thermoswitch). If the lamp tests OK, then test the thermoswitch.
> If the thermoswitch tests OK then check the AC block.
> Goto www.printerworks.com, they have complete exploded diagrams of
> everything there.

Thanks VERY much...that's really helpful. I'll take a look....