What might have happened here? Power Surge

  Jester2K 09:57 17 Feb 04
Locked

On Sunday night all the lights and power in the Sutton, London area went out and back on again 3 times in half an hour. Each time it was out for less than a second.

A client rang up because his PC was "dead". He had been working on it when the first outage occurred. After that the PC wouldn't boot.

I popped over yesterday evening to look at it.

Pressing the power button did nothing.

Checked the fuse in the power lead - OK

Checked the PSU with the standard paper-clip test - OK

So conclusion was some sort of terminal hardware failure. But what? MoBo, processor, RAM, all of them?

I was explaining the tests i had done and showed the PSU firing up OK and moved onto the next step of explaining that the hardware would need testing. I plugged the PSU back into the MoBo to show that although the PSU was working the PC just wouldn't fire up and as i pressed the power button to show it was dead the PSU fired up!! Then the CPU fan started, then the floppy drive whirred for a second, then the PC went through POST and beeped once. Then after about 30 seconds the hard drive started to whirl away.

2 minutes later (after scan-disk completed) the PC seemed fine. No errors. No problems.

Does removing the PSU connector from the MoBo reset something?

We'd love to understand what fixed the PC!

Any ideas?

  JIM 10:50 17 Feb 04

With out going into my bios at present,i believe there is an option of a setting for startup after a power cut.Will check it out for interest shortly.

The link may help? (next page) or may not.


After power failure (IN BIOS?)sets what you want your computer to do when power is restored after an interruption. You can set your system to switch on and reboot or stay off. Select the former if you want your computer always to be ready and waiting for you. Choose the latter to play it safe, so your computer doesn't keep trying to switch back on during brief periods of power restoration or so that you know the power has been off.

  georgemac 11:05 17 Feb 04

I've seen that setting in the BIOS but never really paid any attention to it. We're getting a power outage tomorrow for most of the day, but I should have them off before they flick the switch!

Jester2K - be grateful if you could enlighten me on the paperclip test - I may find it useful in future

  JIM 11:16 17 Feb 04

I am geting forgetfull.-no excuse.


click here

  Jester2K 12:00 17 Feb 04

Jim - interesting... I might look into that. Thing is we didn't touch the BIOS. It just came back to life (although it took over 24 hours)

georgemac - The Paperclip Test for a PSU. If a system won't boot and you suspect the PSU you can test it with a Paper-clip. Find one covered with a plastic coating. Straighten it out and then bend in half. Strip 1 cm from each end of the paper-clip.

Disconnect ALL power from the PSU. Insert one end of the paper-clip into the hole connected by the green wire on the PSU MoBo connector. Put the other end in any of the black connectors. Switch the power on for one second. If the PSU is OK it'll fire up. If its dead, it won't. This tests the PSU because it takes all the comonents out of the loop.

  georgemac 12:15 17 Feb 04

thanks, stored for future reference.

This thread is now locked and can not be replied to.

How to get Windows 10 for free | How to install Windows 10: There is still a way to avoid paying…

1995-2015: How technology has changed the world in 20 years

Hands-on with the Star Wars fighting drones you can fly yourself

15 macOS Sierra tips | How to use macOS Sierra: Secret tricks and best new features in Apple's new…