Scanner Kills Computer

August 7, 2007 6:26 AM

My scanner fried my motherboard, was this to be expected? Can it be prevented? Do I assume the scanner is dead too?

I have a Canon ColorPage scanner, which is USB1, and has it's own power supply. On the weekend I started up my computer to scan some photos and realised that the scanner wasn't plugged in, so after windows had booted I went to plug the scanner in, upon the USB plug contacts touching the socket (or may have even been the case) the whole computer turned off.

Now it wont turn on. I tested PSU and MB separately and have concluded that the motherboard has been fried (and probably the RAM and CPU as well). They were all out of warranty, so I've resigned to ordering new parts (I'm currently praying that the HDDs are fine!)

Now, will my new computer be at the same potential fate? And what might have caused this? The scanner was plugged into a different wall socket than the computer PSU was, and had been plugged in for several days, previously upon plugging in the scanner the whole computer would suddenly reboot,. This occured once or twice before but I had always assumed it was a driver conflict, or a 'feature' that came free with Windows.

I'm using a Thermaltake Armor case, if that's of any relevance, and it was the front side USB socket.

If the scanner is to blame in this case, then would putting a USB hub between the computer and scanner mitigate the damage? Or should I write the scanner off as a deathtrap?

I was berated by my IT consultant father for not plugging it in before turning the computer on, and that, apparently that's the cause. But I have doubts about this... doesn't sound like normal behaviour...

posted by chrisbucks to computers & internet (5 comments total)

It's not normal behavior. One of the major points of USB is that it's hot-pluggable.

A USB hub will probably shield your computer from any malfeasance on the part of the scanner, but to be honest, I would call Canon. However you rig it, it could cause damage. It's already proven itself to be a menace.

Before jumping to conclusions, though, have you used that specific port before with other devices without issue?
posted by invitapriore at 6:59 AM on August 7, 2007

That's not normal behavior for a USB peripheral. As invitapriore said, it's supposed to be hot-pluggable.

I did have something similar happen once, many years ago, plugging-in a serial device while the computer was on. I crawled under the computer desk (dragging my knees on the carpet) and fried it with static electricity. Depending on the circumstances, that could be a possibility.
posted by EmptyK at 7:45 AM on August 7, 2007

probably just shorted out when the connector made contact with the case and the motherboard. that would be my guess.
posted by yeoz at 7:48 AM on August 7, 2007

Hmm, this reminded me of a problem I had with my scanner (also a cannon). I noticed that if when I was plugging it in, if I held it close to the case it would spark. A while after this (I ignored it for ages, maybe not a good idea when it could also shock me if my finger was in the way of the case/plug) I had to replace my motherboard because the keyboard input was acting strange. The new motherboard works fine, but I've never tried the scanner with it.

I'm certainly thinking of getting a new scanner before too long - I'd rather not chance just using a hub. It's probably cheaper to get a new scanner than have to replace all your other equipment!
posted by kg at 9:52 AM on August 7, 2007

(and probably the RAM and CPU as well)

This is actually very unlikely. Of course they aren't very useful without the motherboard, but somebody will probably want them..
posted by Chuckles at 9:20 PM on August 7, 2007