Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a custom built PC using a Gigabyte GA-EP35-DS3P motherboard with a Q6600 CPU. For the last 2 days it has got itself stuck into a POST loop. Saying that, I don't think it actually got in to the BIOS.

It repeatedly lit up the LEDs and then not much more. Sometimes I could see the CPU fan twitch.

Today I re-seated the DIMMs and it powered up straight away. Could this be a sign of an impending hardware failure?

The PC is hooked up to a UPS, so I don't think it's a power spike or anything like that, as I have 2 other PCs on the same UPS and they're both fine.

Yesterday, the first time this happened, I was getting a message which I think said "Scanning BIOS image on hard drive". I've been building and using PCs for well over 25 years and that's a new one on me!

I don't think it's an over heating problem, as when the PC does finally boot up the CPU is running at 35-40C.

Any help or suggestions would be greatly appreciated.

share|improve this question
up vote 2 down vote accepted

Having just had some electrical work done in the house and being forced to "go dark" (unplug everything in the house) for a circuit test to be done. I have been forced to fix this issue.

First I tried reseating the memory, then the video card, then holding the reset button. I also tried pressing reset when it stayed powered up for more than 2 seconds. In desperation I unplugged everything apart from the motherboard (I have a modular PSU, so it was easy to do).

Eureka, the PC powered up and told me it had no O/S. PROGRESS!!!

So, I started plugging things back in, same problem again. So, I tried plugging in each molex connector into the modular PSU after the PC had booted with none of them in. Aha, one of the leads caused the PC to reset. The only thing on that power lead was 3 SATA hard drives, hardly overloading it. So, I swapped those over to another power lead, whadayaknow it works.

So, all this crap I've endured was down to a dodgy power lead. The odd thing is was working for a long time before this started happening. I can only assume I had the cable over stretched, that and the cables might be cheaply made has "worn" the cable out!

share|improve this answer
Since "fixing" the PC by removing a faulty cable it has got worse. It now just says "Scanning BIOS Image in Hard Drive ...". I'm going to try a CMOS reset today, fingers crossed it works .... – Antony Scott Sep 19 '10 at 6:49
I did a CMOS reset, I then started getting useable BIOS beep codes, 3 then 8. I know 3 was memory problems, so I've pulled the 2nd pair of sticks out and it booted up. Now I can replace the memory and carry on. phew, finally! – Antony Scott Sep 19 '10 at 13:42
I finally got around to replacing the faulty RAM the other day and it's been fine ever since. It's quite shocking how much difference having the extra 4GB makes. The PC is so much more responsive now. – Antony Scott Dec 16 '10 at 16:00

Sounds like it's BIOS corruption. Odd as you've got a UPS, but could've been a short on a mis-seated cable caused it. Try this site

Also try re-flashing with a new BIOS. If the BIOS is corrupted you could also clear the BIOS settings first by unplugging the battery, then try re-flashing again.

If you can't even get to re-flash your BIOS as its corrupt and it is looking for the backup on the hard drive, put a BIOS image (*_.bin) on your HDD, or on a spare HDD and plug it in, on a USB stick even? And give that a go.

You'll have to setup your BIOS again, such as RAID, boot sequence, etc.

share|improve this answer
I don't think it's that, unless the Dual BIOS feature of the motherboard has failed somehow – Antony Scott Jun 13 '10 at 20:14
Maybe some Dual BIOS systems will try the first BIOS a few times then fall back to the secondary. I suggest the re-flash as well. – TuxRug Aug 8 '10 at 23:11
I stand corrected, see my comment of my own answer – Antony Scott Sep 19 '10 at 6:51

Do you have a speaker connected to the mobo?

This is what the POST Beep-codes are for. If you connect a speaker or piezo-buzzer to the speaker header on the motherboard, it should signal whats wrong for you.


share|improve this answer
if it fails to boot again tomorrow morning (I don't use it much during the weekend) I will try that. thanks. – Antony Scott Jun 13 '10 at 20:13
It does have a small piezo buzzer attached, and I am getting 3 "clicks" then it reboots. But, today it booted fine got all the way in to windows but then the screen became corrupted and it rebooted itself and went back in to the post loop. So, I'm thinking bad memory stick. I'm going to try booting it up with a rescue CD to test the memory. – Antony Scott Jun 14 '10 at 8:22
Is it clicking or beeping? It should be a clear "beep". Three beeps generally seems to indicate a memory error, but it varies depending on BIOS version. – Fake Name Jun 14 '10 at 8:57
it's not a clear beep, as when it does boot I hear one clear beep which means all is well. – Antony Scott Jun 14 '10 at 9:31
Huh. That sound bad. It could be a mobo problem. There is very little hardware involved in producing the post beeps, which is why they're used for diagnostics - little to go wrong. Just to double check, you have reseated everything (well, except maybe the CPU), right? – Fake Name Jun 14 '10 at 9:44

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .