Computer occasionally hangs at POST

[Nater]

My computer occasionally will hang at POST. It will detect the processor, then when it goes to detect the memory it will hang. The first time it did this, I noticed the ATX power connector was slightly loose. The second time, the connector didn't seem loose but disconnecting it and reconnecting it fixed the issue.

Is there anything else that could be afoot? The 24-pin cable isn't modular on my power supply, so doing any sort of voltage drop or resistance testing on the wires would require cracking open the PSU and voiding the warranty. I'm not ready to do that.

I think I'm going to take a look at the motherboard itself this week, see if there are any problems with capacitors, chokes, ect. Also should probably run Memtest just to be sure, 4GB of my 8GB died months ago (still haven't sent it back) and I wonder if this kit could be dying as well. I kinda doubt that, I don't get any memory related problems in Windows.

[Steve R Jones]

Appprox how often is occasionally?
If its once a month - it could take YEARS to see if any suggestions work or not.

[Nater]

I only restart my computer once or twice a week, so it doesn't happen very often. It's happened twice in the last four months, so saying I restart the computer twice a week...we'll say once every 30 restarts or so.

[Steve R Jones]

So...If we suggest trying "THIS->XXXXX" it could be many weeks before you know if it helped or not...

I wouldn't mess with an issue that doesn't happen very often...Replacing the PSU, Case Buttons or Mobo in that order would be the thing to do if you really are concerned about it

[Nater]

Well, it's starting to happen more. I just spent 15 minutes trying to get the thing through POST. I pulled the 24-pin a couple times to no avail, then I pulled the memory. I pulled DIMM #2, didn't work. I pulled DIMM #1 and it booted. I put DIMM #1 back in and it booted.

I think it's probably either the memory or the DIMM slots themselves. I guess it could be the Northbridge as well. The strange thing is that I have no instability once I am in Windows. The machine runs fine for days or weeks on end.

[Nater]

Alright, I have some more information. I tried swapping in various memory kits when it did it the last time. I tried the original 2x2GB Corsair kit (DDR2-800), a 2x1GB Geil kit(DDR2-1066), and a 2x1GB(DDR2-800).

Corsair 4GB: POST stalled at memory check.

Geil 2GB: Would not POST, this memory has never worked with a P35 board.

Corsair 2GB: POST stalled at memory check.

I thought that I was screwed but then I pulled my Corsair 16GB flash drive from the front USB port and it started up fine. Explain that one, that's a stone cold WTMF.

[Steve R Jones]

I have a Dell at home that hangs at post if a flash drive is plugged into one of the front usb ports..Go figure...

[Nater]

Can you even think of a reason why that would happen? I can't reason any cause for a flash drive inserted into any USB port causing the POST to hang up. But you're the Microsoft MVP, maybe you can. Strange phenomenon none the less, but I'm glad it's not the memory, motherboard, processor, or power supply. Especially not the motherboard and processor, I got a really good pick out of the early Q6600 G0 litter.

[LordVampyre]

hows your cmos battery?? might be time to change it out

[SE_Saga]

Can you even think of a reason why that would happen? I can't reason any cause for a flash drive inserted into any USB port causing the POST to hang up.

The only time something like that happened to me was due to the PSU. There were enough wattage for the whole system, but the amperage wasn't right. By inserting a USB device (flash pen or whatever), it pulls some extra power that otherwise wouldn't, so that caused the freeze at POST.

However, it happened at a random POST point, not exclusively during the memory test, so your situation sounds specific to that test... you tried different memory sticks, so it's safe to say it's not the RAM, but it could be a corrupted BIOS or an actual physical flaw in the chipset/motherboard.

[bldegle2]

I have experienced the same problem, spent days/weeks trying to figure it out, did the mems swapout scenario, boiled down to a USB device that suddenly went wacko at boot.....

Weird...

Glad you found the problem and fixed it on the cheap...

laterzzzz........

[CaTaLyST]

Maybe the system is trying to scan that flash drive to see if its bootable. That's my guess. In today's computers, USB devices are often a bootable option now.

[morphid]

Does it always boot OK when you have the flash drive unplugged? If that's the case then it could very well be that the PC is trying to boot from it like CaTaLyST said. Try disabling boot from USB legacy device in the BIOS.