I've got a strange problem that very occasionally (maybe once a month) when I plug something in to the front USB port on my computer, the computer suddenly restarts. This also happens sometimes when I touch the front USB ports. This has been going on for a few years and a lot of the components in my PC have changed.

  • I thought it was my home wiring, but I moved last year and it still happens.
  • I thought maybe it was the motherboard, but that was upgraded 9 months ago and it still happens.
  • I thought it was my case, but I changed that recently and it still happens.
  • I thought maybe it was my PSU, but I upgraded that yesterday and it still happens.

I'm pretty sure this is an electro-static thing, but I thought that modern computers have protection against this sort of thing. Maybe I should move my case off the floor (carpet) and stop wearing songs all the time.

Edit: Just to clarify, this is a computer that I built. The components have been upgraded throughout the years and it's not much the same computer anymore.

This doesn't happen very often, but it is annoying, because I don't know what the cause is. Anyone have any ideas?


I've seen this before, and the end result was a faulty USB port.

When you plugged something in it would do exactly what you are describing. It definitely makes me think faulty port in this case, since you said sometimes when you touch it the PC will restart.

Luckily for us the laptop in question was still under warranty - I would ask if this PC is still under warranty, but the things you have done to it make me think not.

You might just want to just check the cables are properly pushed in at both end of the USB port, however in your case I wouldn't get your hopes up.

  • Well, I built it so some of the components are under warranty. The cables are plugged in correctly and it's not the port, because this happened with two different computer cases. – Mark A. Nicolosi Feb 8 '10 at 0:36
  • next thing to check is the motherboard ground. Make sure the screws that connect the motherboard to the PC case are correctly installed. They should touch the small metal circle around the hole on the MB and connect it to the PC case. – Chris Nava Feb 8 '10 at 3:46
  • Two different motherboards and two different cases. All using the stand-offs and screws that came with it. I'm wondering if a wireless mouse dongle could be the cause (it's always plugged into the front)... – Mark A. Nicolosi Feb 8 '10 at 5:11

I'm also having this issue with the front USB ports on my antec 1200 case, so I'm going to throw my guess in and say it's faulty wiring/grounding on the front panel. If your problem is with your front panel, try the back panel. If the problem stops, you need to open your case and make sure the front panel is connected properly. Although it may just be faulty.


I had a similar problem plugging my Motorola Droid into the front USC port on a Dell desktop. The problem was related to the Droid pulling more power than the front port supplied causing he reboot.

Try using a powered hub or using one of the back ports. Make a note of what device does it. It may be something drawing too much power.


I had a computer many years that had behavior similar to this. It would reset when applying extra load on anything using 5 volts. Moving an optical mouse causing the led to turn on would even cause it. I replaced the power supply and all was well.

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