# Laserjet repair 'Service 50' error

O

#### Oppie

Jan 1, 1970
0
Found a good site for printer repair information and parts:
www.fixyourownprinter.com
Not only do they sell repair kits but if you look under the reference links,
there are service manuals for many printers.

I was getting an intermittent 'service 50' error (fuser) for the last few
years on our Laserjet 4MV. We had replaced the fuser about four years ago
because the paper kept sticking to the roller. Worked very well for the most
part. When we got the error again, I tore into it and found that the door
interlock switch was flaky. This is a Chery F85, three-pole plunger switch.
One set of contacts is in series with the fuser lamp and the contacts were
slightly burnt. Made it seem that the fuser was open and threw the code.
Pain in the tail to get to the switch but got it out, cleaned and burnished
the contacts then applied 'Deoxit' to them. Switch is obsolete but was lucky
that it could be disassembled to clean the contacts.
switch in series with the fuser lamp getting intermittent opens. Produces
the same service 50 error.

N

#### Nico Coesel

Jan 1, 1970
0
Oppie said:
Found a good site for printer repair information and parts:
www.fixyourownprinter.com
Not only do they sell repair kits but if you look under the reference links,
there are service manuals for many printers.

I was getting an intermittent 'service 50' error (fuser) for the last few
years on our Laserjet 4MV. We had replaced the fuser about four years ago
because the paper kept sticking to the roller. Worked very well for the most
part. When we got the error again, I tore into it and found that the door
interlock switch was flaky. This is a Chery F85, three-pole plunger switch.
One set of contacts is in series with the fuser lamp and the contacts were
slightly burnt. Made it seem that the fuser was open and threw the code.
Pain in the tail to get to the switch but got it out, cleaned and burnished
the contacts then applied 'Deoxit' to them. Switch is obsolete but was lucky

Contact cleaner is a one way ticket to the dumpster. If a contact is
worn out the only viable option is to replace the switch or connector.

O

#### Oppie

Jan 1, 1970
0
Nico Coesel said:
Contact cleaner is a one way ticket to the dumpster. If a contact is
worn out the only viable option is to replace the switch or connector.

Agreed with contact cleaner that affects the contact resistance long term.
Deoxit has proved to work rather well in the applications I've tested it in.
Besides, as written, switch is obsolete and no longer available.
Check it out and see what you think http://www.caig.com/

N

#### Nico Coesel

Jan 1, 1970
0
Oppie said:
Found a good site for printer repair information and parts:
www.fixyourownprinter.com
Not only do they sell repair kits but if you look under the reference links,
there are service manuals for many printers.

I was getting an intermittent 'service 50' error (fuser) for the last few
years on our Laserjet 4MV. We had replaced the fuser about four years ago
because the paper kept sticking to the roller. Worked very well for the most
part. When we got the error again, I tore into it and found that the door
interlock switch was flaky. This is a Chery F85, three-pole plunger switch.

Did you check Honeywell or Panasonic? IIRC they make these kind of
switches. Digikey, Mouser, Farnell, etc may carry them.

E

#### ehsjr

Jan 1, 1970
0
Oppie said:
Found a good site for printer repair information and parts:
www.fixyourownprinter.com
Not only do they sell repair kits but if you look under the reference
links, there are service manuals for many printers.

I was getting an intermittent 'service 50' error (fuser) for the last
few years on our Laserjet 4MV. We had replaced the fuser about four
years ago because the paper kept sticking to the roller. Worked very
well for the most part. When we got the error again, I tore into it and
found that the door interlock switch was flaky. This is a Chery F85,
three-pole plunger switch. One set of contacts is in series with the
fuser lamp and the contacts were slightly burnt. Made it seem that the
fuser was open and threw the code. Pain in the tail to get to the switch
but got it out, cleaned and burnished the contacts then applied 'Deoxit'
to them. Switch is obsolete but was lucky that it could be disassembled
to clean the contacts.
switch in series with the fuser lamp getting intermittent opens.
Produces the same service 50 error.

Do you have room to add a relay? You could extend the life of the
switch by having it switch relay coil current instead of fuser
lamp current.

Ed

O

#### Oppie

Jan 1, 1970
0
ehsjr said:
Do you have room to add a relay? You could extend the life of the
switch by having it switch relay coil current instead of fuser
lamp current.

Ed

Many more important things to do about the lab than fix the printer. No
budget to replace it (it's a large format, 11x17). When it's working, has a
GREAT halftone range. I read that it was originally sold for graphic arts
and uses a Canon print engine. I print out all the schematics and artwork on
it. I think that we got it as a close-out special about 10 years ago at
$1500. There is NO space in there at all to hack something in. Absolutely amazing how HP squeezed all those parts into such a compact format. If I went the relay route, would have to put the it outboard. For now it's working and I'll keep an eye on it. Regards - Oppie N #### Nico Coesel Jan 1, 1970 0 Oppie said: Many more important things to do about the lab than fix the printer. No budget to replace it (it's a large format, 11x17). When it's working, has a Not even second hand? The situation may be completely different over there but over here the large HP printers are sold pretty cheap. Especially old models like you have. OTOH a new printer isn't that expensive anymore. I paid less than$300
for a new HP printer (business model) including a network interface.
My previous printer was over $2000. O #### Oppie Jan 1, 1970 0 Nico Coesel said: Not even second hand? The situation may be completely different over there but over here the large HP printers are sold pretty cheap. Especially old models like you have. OTOH a new printer isn't that expensive anymore. I paid less than$300
for a new HP printer (business model) including a network interface.
My previous printer was over $2000. Appreciate that. I did check a couple of years ago and B size laser printers weren't cheap. Business really stinks here and no budget for anything. At present, I get paid for 32 hours and wind up working (on my own initiative) 40+ just to get product into the pipe. Last four years here have been a joke. Time for a new president that will really create a positive economic climate. I would have taken Kane over Gingrich but looks like Romney will be the Republican choice. Where in the Netherlands are you? Part of my family hails from Amsterdam. N #### Nico Coesel Jan 1, 1970 0 Oppie said: Appreciate that. I did check a couple of years ago and B size laser printers weren't cheap. Business really stinks here and no budget for anything. At present, I get paid for 32 hours and wind up working (on my own initiative) 40+ just to get If I may ask: what is your employer's core business? product into the pipe. Last four years here have been a joke. Time for a new president that will really create a positive economic climate. I would have I'd rather go out and find a way to make money than having to rely on politics. And yes that is difficult. Anybody who says that the US should go back to production work is an idiot. Education is the key to stay ahead. China and India are already doing the production and there are many countries waiting to take over when they get too expensive. If you want to be succesfull you either have to mass produce a product or find (stumble upon) a local niche. Where in the Netherlands are you? Part of my family hails from Amsterdam. I live close to Amsterdam but that is mainly due to my wife wanting to move. My family originates from and around Amsterdam though. J #### josephkk Jan 1, 1970 0 Not even second hand? The situation may be completely different over there but over here the large HP printers are sold pretty cheap. Especially old models like you have. OTOH a new printer isn't that expensive anymore. I paid less than$300
for a new HP printer (business model) including a network interface.
My previous printer was over $2000. Network interfaces are almost standard on laser printers in the US now. I bought a duplex laser printer with wired and 802.11g network for about US$200.

?-)

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