Question : 4 out of 5 network printers lose connectivity after 5 minutes....

Alright guys, this is a very strange one indeed.  At my office building, we have 5 HP LaserJets, and as of yesterday, only one will work correctly.  We have a win2k domain, and all the printers are connected to the network, shared on the DC, with fixed IP addresses.  Since yesterday, the printers will work for about 5 minutes, then lose network connectivity.  I was off yesterday, so I didn’t get to start troubleshooting until today.  Once the printers go down, you have to turn the power off, then back on, and for around 5 minutes it would work fine.  I turned one off and began pinging the printer, and would get replys, then after 5 minutes, I’d get time-outs.  I’d turn it off, then back on, and would get replys for another 5 minutes only.  This was repeated on all 4 of the 5 printers.  

I was thinking there was some issue with one of our 16-port switches, so to rule that out, I plugged in one printer into my little 5-port switch, and my computer into that same switch; taking the router and other switches out of the equation.  Same issue.  So in effect, I had a direct network connection to that one printer.

As a workaround, I took a laptop and connected it to the printer using a standard parallel cable.  It worked perfectly.  I shared that printer through the laptop to the domain and everyone can print to it fine, and it doesn't time out.  Unfortunately, I only have one spare laptop, not 4.

What could possibly be the issue here?  No other computers on the network (22 of them) have any network issues whatsoever, or any other issues for that matter.  So I don’t think it could have been some sort of power surge or something like that.  It’s not the switches, not the router, not the network cabling or anything like that.  And it’s not a driver issue because the laptop has the same drivers as everyone else is using, but the drivers wouldn’t even matter because I can’t even ping the printers after 5 minutes.  Does anyone have any idea what I could possibly try to maybe resolve this?  Thank you very much for your help, I really need it on this one :).

Answer : 4 out of 5 network printers lose connectivity after 5 minutes....

It looks like the jetdirect cards could be interchangable between the different models, but the proof will be that when you pull the cards, they will look different to each other, that the plug fitting on the end is in the same place with the same number of pins and that the card fits into the different printer, and of course powers up.

HP 4100 should have a J4169A card
HP 5000 should have a J3110A or J3111A or J4169A card
HP 5500 should have any of the above

There are also firmware upgrades available from HP, which could be a good idea as the firmware could have been screwed with a power spike.

I have service manuals available (PDFs) for the 4100 and 5000 if you need them.

Looks like you might have a full days work ahead of you. :))