System reboots randomly, need help fixing.

[kempodragon]

Back in July, I was doing an overnight encode when my house had a power outage. Since then, my system has gotten progressively unstable. After backing up my critical data files, I first tried repairing the hard drive with the Win2k cd. It would work briefly and then start crashing or rebooting. I got all sorts of different errors, like page faults and irq conflicts, but nothing consistent. It got so bad that it rebooted continuously at one point, and when I finally got it to stop, Win2k told me that it could no longer repair the drive. I then did a comeplete reformat and reinstall. I thought would fix it, but it still refused to behave, even after I did a second reformat and reinstall. I then used my second hard drive and made it my system drive. After formatting and installing, everything seemed ok. It was rock solid stable and I thought finally the problem was solved. Three days ago, it started rebooting again, and this time it even once refused to show the bios screen. Currently, I have to repair the drive at least once, and I've done several chkdsk's to make it stable enough to use the web.

I fear that the motherboard received a power spike and has been damaged. I already plan to replace it and the power supply. I also plan to get a surge protector/UPS to prevent this from ever happening again. What I need to know is should I also replace the memory chips or processor as well? How can I tell if any other cards were damaged? Also, what about the hard drive, both previous and current? Can they be used again, or are they also damaged? I've had power outages before, but I've never had so much trouble recovering from one. Your help is greatly needed and appreciated.

[Doom9]

when I reed reboots right now I automatically think of blaster.. make sure you got that base covered before you blame your hardware. As for determining the problem.. that's a really annoying issue. There are ram test tools (which are slow as hell), which can help you rule out ram as a problem cause (I once had a similar problem.. but my computer froze only when playing divx so unless I watched a divx movie everything was fine). From that point on, if you know a guy who has some spare computer parts, or a computer shop owner who's nice enough to check up on your pc or lets you borrow his workspace for a while while you selectively exchange computer parts, you're well off. If not, I'm afraid you pretty much have to do what I did.. start replacing the cheap stuff, and gradually your computer turns into something new.. Murphy says that the component that's screwed will be the last one you check (it happend to me.. who'd blame the mainboard?). Not very encouragin, I know.. but nevertheless.
BTW.. computer parts should be able to handle power surges, but there's a limit to everything (in June a storm fried my onboard LAN card, one Switch port and the LAN port of my cable modem), but the rest of the system was fine (and I have tons of electronic equipment in my room..). MY point with this is that if you're going to decouple your computer from the power network.. better get a UPS capable of handling all the devices connected to your PC.

[Ramirez]

Replace your PSU *ASAP*, and only if it'll fail fixing your problem proceed with checking/replacing other components of your system.

[erbuk]

Unfortunately I have a rather large experience in computers damaged by lightning strikes. A power spike caused by other things should very likely generate the same problems.

The modem is always burned out and if it’s an internal modem it can cause problems with other hardware. Usually it causes a shortcut in the PCI-bus and the computer refuses to start. But it can also cause more fuzzy problems. So remove the modem if you have one.

The second thing that happens is that the memory chips fails. They usually runs fine for a few days after the strike but then gradually starts to fail causing exactly the problems you mention. I should think that this is your main problem. Replace the memory chips!

Damage to other components, like the power supply and motherboard, are very rare unless the lightning strikes very close. In those cases you will most likely feel a heavy smell of burned electronics when you open the case.

[Ramirez]

hmm, from my experience () the PSU and the mainboard would be the first components who takes the heat during lighting strikes, then in terms of probability comes hard drives,CD\DVD drives,various internal cards such as modem\VGA\ Net cards\ RAM Modules etc...()

And no,The PSU or MB doesn’t have to spread a heavy smell of burned parts to be totally dead or partially damaged so I wouldn't take it as the only indication.

Anyway I am pretty sure that in this particular case we're talking about a damaged power supply unit which causing system instability and I'd suggest to kempodragon starting his troubleshooting sequence from replacing the PSU.

[erbuk]

Maybe we should place bets :D

I have repaired 9 lightning damaged computers this summer. In two cases replacing the modem was enough in the other cases I had to replace the memory modules too. In one of the computers the parallell port was damaged. No broken psu:s.

Components connected to two separate electrical systems, like modems and base stations for cordless phones are always the first to go in a lighningstrike (unless you unplug one of the cables when then the thunder starts).

[kempodragon]

Well, I FINALLY got my system to behave. First I replaced the power supply. System ok for a time, then misbehaves. Replaced memory, turn system on, total failure. No boot up whatsoever, just fans turning on. Had to wait two weeks until I could get a new motherboard. After rebuilding my system, computer is now running quite nicely. Murphy had a big laugh at my expense and hopefully he'll go pester some other dumb schmuck for awhile.:mad: Note to anyone building new system, make sure you have a surge protector/battery back up to protect all that lovely new hardware.