Laptop NIC's frying: 3rd one at this desk!
Posted on 2005-05-04
This is by far the most bizarre situation I've encountered in my 10+ years working in IT Support.
We recently moved a group of users to a new space in our office. We had to have new CAT5e cable run to this area, as well as new power lines and cubicles. Most of the guys in this area are using the R40 IBM Thinkpad.
Well, about 1 month into this move, 1 of the users comes to us and says his on-board NIC no longer worked. Puzzled, we took a look at it and confirmed it wasn't working. I noticed one of the Ethernet pins was just a little bent (not much though), so I assumed that must be the problem. We pulled his hard drive and place it into an identical R40 Thinkpad. I tested the NIC on this new laptop and everything looked good. Problem solved right? Wrong.
About 2 weeks later, the same guy came back and said his NIC stopped working on this new laptop. So now we're thinking "OK what's this guy doing over there.." We took this 2nd laptop and examined the NIC carefully. No bent pins or anything. He's pretty responsible and would have told us if he had done anything careless such as pick up the laptop while it's plugged in. Seeing that this was laptop #2, we went ahead and swapped out the patch cable at his desk as well as the patch cable on the switch to his port. Our network admin took a look at the switch port and didn't see any errors. So, we concluded this was just a weird coincidence. We swapped out laptop #2 with laptop #3.
Today (about 1 week later), the NIC on this 3rd laptop has now stopped working. It was working fine, now it's not. None of us have heard about voltage traveling over CAT5e cable then frying a laptop. I've heard of a bad nic causing a port on a Cisco switch to disable itself, but not the other way around. This 3rd laptop is doing the same exact thing as the other 2. The NIC shows up in Device Manager, so the drivers are loaded. When you plug a cable into it you get no Link light. Windows thinks the network cable is unplugged. It's basically just fried and dead. All 3 of them.
We decided to hook up a Fluke Microscan tester to his jack at this desk to test the run between his desk and the patch panel. No errors...all pairs are clean.
So...we swapped out laptop #3 with laptop #4 today (identical R40 IBM ThinkPad). We also connected a hub to his jack and have the laptop connected to the Hub. This way, if something is causing a network device to fry, we are willing to sacrifice this hub to protect this 4th laptop.
So, anyone here ever heard of something causing an on-board NIC to fry over and over? There's hardly any voltage at all going through a CAT5e run, so it can't be that. I noticed that his surge protector is sitting on his desk and it wasn't before he moved. It's about 12 inches away from the back of his laptop...but c'mon that couldn't be it, could it?
As an FYI, when we attempt to boot to the network from a DOS Boot Disk, the NIC still wont work..so that pretty much eliminates any software-related issues so re-imaging, re-installing the drivers, etc. wont help at all. The CAT5 that was run to this new space is about 150 feet and is all in 1 bundle in the ceiling. I’m wondering if this bundle is near a power source or motor somewhere in the ceiling, and a few cables are picking up a load, and then transferring this voltage to the laptop NIC. At this point, it could be anything.
Any suggestions as the possible cause of this are welcome. Thanks!