So my pc is breaking down and I don't have a clue (in Off-topic)

Over the past few weeks I have a problem with my PC and can't get to figure out what is wrong and it is causing me downtime on CB mostly...

The thing my pc does is this: it reboots without warning without error and even a PC repairman does not know what is wrong with it. It reboots in Windows, but it also reboots in bios, during start-up and it is neither time nor temperature related


I can tell you all things which it is not:
it is not the CPU overheating, temperatures are ~35 C.
it is not the video card, I even have tried a new one which did not help a bit,
it is not the PSU, I have put in a new one, same problem,
it is not the cdrom player, after completely disconnecting it, it still reboots,
it is not the HDD, after disconnecting it, it still reboots,
it is also not the sound card, after removing it from the system, it still reboots.

That leaves 3 components which could be faulty:
CPU
Main board (or mother board)
Memory

Now memory isn't it either, the pc repairman had tried different memory, still rebooting, so it's either the main board or the cpu which is broken. Neither have been flagged with diagnostic programs as being broken in any way either.

So I'm frustrated and absolutely clueless...

i think its because the mother board or main board has a broken fault, like its bent a bit. :o

That could be the problem, but how would such a thing 'break' so all of a sudden and why would it cause random reboots?

maybe a small bent might make a cord or so unconnect, so it will random reboot cause of that.. everything is possible.

Tried re-installing windows?

Reyth:

That would not solve the problem since the system restarts even with no hard disk connected, i.e. before even mentioning Windows on the machine at all, so it's not a software issue.

Even more because it also reboots when trying to start-up or sitting nice and idle in BIOS.

Wow.

Download and run Memtest86+, it's probably either faulty memory or a faulty DIMM slot.

Here's a tutorial I found via google:
http://www.overclockers.com/forums/showthread.php?t=409152

wonder how he downloads and run the memtest if it auto reboots even when he starts it up .-.

That has been tested already and my memory came out clean. The problem even occurs when putting in brand new memory. >.<

That's why I suggested it was a DIMM slot issue, which Memtest would also detect.

@Quyen: How's he on this site?

Silly question, but, have you tried another power cable, and/or a different plug socket? It could be "dirty" power.

B-loved, u really had to ask that? :p

Which question? The "how is he on this site"?

It was rhetorical, my point was, if he's on this site, he can download a file.

As to that question, I've got a spare laptop and the problem is not timable, it could be that it reboots in 2 seconds, or in 2 hours so it's not consistent.

And for the other power cable, it has been tested at a completely different location with different cables and everything, still rebooted...

Is it a self-built or a pre-built? I know I've had problems with the front connectors coming loose, it's very easy to short the pins for a reboot if the connector's loose.

I can't think of much else, which suggests a physical fault, probably with the power circuitry of the MoBo.

selt built system, built it in January 2009 and it's been working perfect until a few weeks ago... :(

I bricked the MoBo of my last self-built, with a bad BIOS update. :(

I feel for you. You could try a new one, but it's not really the kind of thing you can borrow to try it out >.<

you could try updating the bios and hope like hell that it doesn't reset during the procedure.

I'm wondering if updating the BIOS would help a mechanical electrical problem. mhmmm

once it reaches the motherboard, even the power is now controlled by software these days. much like our cars, if our main computer goes out the car can quit working even though the mechanical and electrical systems are fine.

True but the power has to go through soldered connections afaik so if that makes the problem, then bios updates won't really help.

to make things more fun: the PC has been on for about 4 hours now without any problem :\

i have seen this exact thing on a computer that i had updated the bios on. you didn't say you had updated but the bios can become corrupted. i would at least go read all of the notes on the bios updates that have been implemented since the bios revision you have and see if you see anything interesting.

Check your spread spectrum settings

Spread Spectrum settings? (how, where?)

dude: http://www.asus.com/Motherboards/Intel_Socket_1366/P6T_WS_Professional/#download

This is from my main board, but I don't see anything special in it.

which bios version is yours?

I think one of the eldest, not sure which but I could check next time I boot the machine.

There's a strong chance some of the capacitors on the motherboard have croaked (or are about to).
You can spot croaked capacitors by either their "bulgy" shape or broken catastrophic failure prevention valve.

http://www.penngeeks.com/wp-content/uploads/2011/04/bad_motherboard.jpg

Image example. Probably not the best, but to give you an idea.

Did this start happening after you installed some new hardware or software?

Run antivirus on it to make sure it's not infected.

check/update your drivers.

open the cover and clean out the dust, and pull out anything you don't need for the PC to work. Make sure all cards are in nice and firmly (including RAM).

Does your MB have a boot up error code?

lastly if you can't figure it out, get a flash drive save what you need to (or transfer to laptop), first run windows repair, then if that doesn't work, format it and put a clean copy of windows on it. (since you have a laptop, you can down load the drivers you will need for your PC and install them from there, in my case, I had to save them to my flash drive then load them).

Mine was doing this a few weeks ago and it turns out that it was a registry error, which could only be fixed with a fresh install.

nope, just all of a sudden.

It does have boot up error codes, but it does not show any error code (as likely there aren't any?)

At this point get your mobo replace is your best option and its still under warrenty if you have buy its in 2009. Lots of retail shop can exchange them if you pay the installation.

I can install it myself, have been building PC's ever since I was a wee lad. I hope they indeed will replace it.

What is the PSU and have check your voltage on your 12V rail.

The 12V rail was ok.

Fortunately I still have warranty for the main board and the CPU. I will be sending both through RMA to the supplier and get it checked out.

The solution would actually be very simple though constitutes with spending a couple of your dough and it would be to get a new machine. haha. Personally, when the motherboard starts to falter, that would be a good indication for you to get a new set. It has been going for almost 3 years already so it served its life and purpose well already.

And of course I'm not satisfied having to spend the same amount of money on a new machine while my machine is still top of the line (sort of)...