Can a power failure only destroy certain parts of a computer?

Question

A few years ago, I was operating my computer during an electrical storm and the power got knocked out. Whenever the power came back on, the computer started up just fine. However, after Windows loaded up, I discovered that all my PCI cards weren't working.

I had a sound card, wireless ethernet card, tv tuner and dial-up modem. Now, it seems none of them work. I've tried hooking them up to other computers and they don't work. Also, I tried putting a working sound card from another computer and it also was not detected.

I assumed the power failure had somehow destroyed anything to do with the PCI slots on the motherboard, including the cards plugged into the slots. It was strange that nothing else was effected including the video card which was in an AGP slot.

Why did the power failure only corrupt the PCI cards and PCI slots?

The problem with the phone line story is that I had stopped using dial up and there was no phone line connected to the modem.

Answer 1

Since your PCI slots do not work I believe that your Southbridge processor has seen its last day. The Southbridge processor controls the communication between the Peripherial Control Interface and the Central Processing Unit.

Answer 2

I agree with Sasha and Jason; it sounds like it was an EMF spike via the phone line to modem. That would explain why all the PCI cards are dead (because they had a common power source). And since a good soundcard didn't work in this computer, your motherboard was gone, too.

It may not have damaged other parts because they were powered from a different line from the power supply. The damage sequence would have been phoneline - modem - other PCI cards - power supply, and it never got any further than that.

This event is a good argument for having a surge protector with battery backup. I got a big APC unit on sale at Best Buy for under $50. The phone line runs through it, too, so no worries about the phoneline route any more. Cheap insurance.

Answer 3

My guess is your problem came from the phone line not the power outage or something plugged into one of your PCI cards.

You should have specified your motherboards make and model.
If we knew that we could look at a diagram and check how the board is layed out. Sometimes the part that controls the PCI's is built into the south bridge of the motherboard, but if yours was then the whole south bridge should have crapped out. It is possible that your motherboard just uses a PCI controller chip that is connected on a bus that runs into your south bridge and that chip could have blown. I am no expert but I think I my answer is very close to the truth. A electronic engineer could probably tell you better.

EDIT:
Arg, I forgot the part about all the cards dying. That would most likely be due to a very high voltage that was applied to the cards. Any voltage in excess of the cards specs would destroy the card. If you put a working card into the system and it stopped working then your power supply might be the problem, that's If you still have the same power supply in. In this case It probably was was not as a result of any external input to the PCI cards. Power distribution inside the PC is not my strong point.What you could do is take a multimeter and measure the Power supply's output at the 20 pin connector.

I wish one of those Hardcore hardware pro's would read this question.

EDIT:

Justin has told me by email that all the cards are suddenly working now. There was a GHOST in his new machine but it's been exorcised. We'll have to put this one in the X-files.

Answer 4

The surge took the easiest path and knocked everything out along that path. Just use a good surge protector from now on and don't be too concerned about the path of the electrical surge.
A strong surge can actually burn out a surge protector and arc right over, and through it.
So get one with a high Joule rating.
They typically come with a guarantee for any loss of equipment that were plugged in and got damaged
Good luck.

Answer 5

The surge came in through the modem, and it probably fried those boards.
Any time you have a storm like that it is best to shut your computer down.

Answer 6

i imagine that your means provide isn t functional adequate you want to improve that. A united statescontinuously enables too to circumvent surges (UPS- uniterrupted means provide-surge protector). In different words your computing gadget doesn t have adequate means. Or it could be a loose contact from interior your computing gadget, make constructive your means provide is linked proper with each and every of the instruments rather with the motherboard.

Answer 7

i don't know the answer to WHY part of the question....but this can happen....and it has happened to my computer as well...

Answer 8

No