New build PC powers on for 5 seconds then restarts

[Lateralis85]

Hi all.

I've just put together a new build:

Intel i5-2500K (for the moment stock heat sink and fan with Artic Silver thermal paste... I'll replace the HSF when I have more money)
MSI P67A-G45 motherboard
Antec 620W "high current gamer" PSU
XFX HD 6850 ("Black edition") graphics card
1 x 320 GB WD hard drive
1 x Samsung DVD burner
2 x 4 Gig sticks of PNY RAM (1600 MHz clock)

When I hit the power switch everything turns on - all fans start, I hear the HDD and DVD burner start up normally and I get 4 (out of four) blue LEDs above the CPU which means "CPU is in four phase power mode", according to the mobo manual. Everything *appears* to start up quite happily but after approximately 4 or 5 seconds the computer restarts - everything powers down for a couple of seconds and then it powers back up again. This on-off-on-off routine continues indefinitely.

I have tried:

* stripping as much off as possible. I disconnected the DVD burner and HDD drive, unplugged the front I/O panel jumpers, removed the reset switch and HDD LED jumpers

* Tried each RAM stick individually in each of the four mobo RAM slots

* reseated the processor and HSF

* switched power cable for the graphics card (the fan powers up on the card with both cables)

* checked for shorts. The mobo is supported in precisely the recommended support holes as documented in the mobo manual - no other support stubs are in the computer case except for those in use. No wires go between the motherboard and its support, nor do any touch the motherboard.

I have installed the beeper/speaker which came with my case but it doesn't beep at all during the power on. That, of course, could just be because of a bad speaker, but I'm still suspicious something is badly wrong.

Anyway, I then Googled around and found the troubleshoot help thread on here, which said to do everything I have already done, except for bread boarding it. I will try that, but right now I'm thinking either PSU, mobo or CPU is DOA. Does anybody have any other ideas or suggestions I can try out to narrow down what might be wrong?

I've just had what might be a fairly mad idea, only because I don't think this is likely, but I'll throw it out there anyway. The RAM I have has a rated clock speed of 1600, but the mobo will only do that with overclocking. Am I correct in thinking that the RAM should just work even at the lower clock?

Any help would be appreciated. I've been without a gaming PC for over 2 months now (moved country - only just have enough now to buy stuff!) and I'm getting a bad case of withdrawal. Thanks.

 

[Blade9030]

you are right about the RAM under-clocking to the MOBO

and i would say MOBO or CPU is DOA

i have had several computers act the same way and in 4 of the 5 it was a bad MOBO and 1 was a CPU

if you think it is the PSU try switching it out with another one if possible

 

[Lateralis85]

you are right about the RAM under-clocking to the MOBO

and i would say MOBO or CPU is DOA

i have had several computers act the same way and in 4 of the 5 it was a bad MOBO and 1 was a CPU

if you think it is the PSU try switching it out with another one if possible

Yep, my gut feeling says it is the motherboard. I'm hoping to elevate my gut feeling to something more substantial though!

I'm going to ask my neighbour if they have a PSU I can borrow to rule that out. If they don't have one then getting hold of one will be tricky. Setting up for the first time in a new country means I'm missing a lot of things that I just had lying around back home, such as spare PSUs.

Ah well. After many different computer builds this is the first one to give me any problems. It was bound to happen at some point!

Anyway, thanks for your reply, I appreciate it. If you have any ideas please let me know!

 

[Lateralis85]

OK, so I was in e-mail contact with MSI technical support yesterday. The nameless person I was talking with said that this on-off-on-off ad infinitum behaviour is to be expected if either the CPU, RAM or graphics card were defective. I've had a defective graphics card and defective RAM module in the past and in those instance I got the relevant beep code but the PC remained powered up. The PC didn't power down entirely before attempting to boot up again. I also know of people who have had other defective components before and every time the PC would remain powered, albeit in a useless, non-working state.

So I'm thinking that this technical support guy yesterday was just yanking my giggle chain (or otherwise didn't know what he was talking about) but I wanted to double check that on here. My question then is: if the CPU, RAM or graphics card were bad, would the PC shut itself down and then try to power up again? (If it is of any significance - I don't think it is - the motherboard has a UEFI BIOS.)

Thanks guys.

 

[soUp_10]

I am having the same exact problem with no luck on any solves. I've read around that resetting the cmos has worked for many people, but not for me. Currently, my ram, video card, and CPU are out of my computer, and am still having the on-off-on-off problem. Battlefield 3 comes out on Tuesday, I need help!

 

[Lateralis85]

I am having the same exact problem with no luck on any solves. I've read around that resetting the cmos has worked for many people, but not for me. Currently, my ram, video card, and CPU are out of my computer, and am still having the on-off-on-off problem. Battlefield 3 comes out on Tuesday, I need help!

Hey. Yeah, I rea about the cmos issue too. I tried that and that didn't fix
my problem either. I tried a separate power supply, ttied removing RAM and the graphics card. The theory being if either was defective leading to the shutdown, with them removed the POST should happen but I'd bet a beep. I still got exactly the same behaviour no matter what was installed and what was removed. I tries with just the processor and motherboard out of the case and still the same.

After that, the MSI technical support guy said I should return the mobo and processor for replacements. Which is what I've done. I should get my replacements next week.

 

[Lateralis85]

So, an update for those that are interested. My new motherboard and CPU arrived today. I've just connected everything and guess what - I still have the same problem. Realistically that leaves me with these possible scenarios

1) I'm unlucky. I've received two batches of bad components.
2) I'm rubbish at building PCs. I don't buy that as I've built, fiddled with, altered, stripped and rebuilt numerous PCs in the past. I may have made an error but I know what I'm doing and am always careful.
3) One of the other remaining components - graphics card, RAM or power supply - is faulty.

Right now I'm leaning towards number 3. I don't think it is the power supply though as I tried a friend's power supply two weeks ago when I first tried to build this PC and I had the same behaviour. I'm going to borrow a digital voltmeter from work to check out the power supply just in case though. I also don't think it is the RAM as I have two sticks and neither work in any slot. It's possible I've got unlucky and have two bad sticks, and I've never had a single bad stick of RAM before *ever* so maybe I am due a bad one... And finally, I'm trying to find a different graphics card that I can use to test.

If that doesn't work though, I think I'll just run in to the forest, live like a hermit for the rest of my life and shun all technology!

 

[Lateralis85]

This is a brief reply from my now working computer.

The problem turned out to be the RAM. Both memory modules are bad. It turns out that with this motherboard, if you have no RAM in the computer, or you have a bad memory module, the computer will continually shutdown/turn on indefinitely and give you no beeps. Strange behaviour, but that we go. The computer lives!

So if anyone else has the same problem, try new RAM!

 

[robotdestruct]

I have been through that and my friend has also gone through that. Both times it was because the ram was not compatible with the motherboard. We had 2 8gb sticks of Viper, but it would only take pairs like: 2 x 4gb or 4 x 2gb for Viper. The manual should tell you what brands and what options of gb sticks will be compatible as well as what speed.

We thought it was bad ram too, cause it would run with no ram or a 2gb stick we had. So we only had a few choices to get 16gb in and it was with Vengence 4 x 4gb sticks to do it. We then put the ram (that we thought was bad) in a different computer and it worked fine. So don't throw that ram away just yet!

 

[ky.snooks2808]

This is a brief reply from my now working computer.

The problem turned out to be the RAM. Both memory modules are bad. It turns out that with this motherboard, if you have no RAM in the computer, or you have a bad memory module, the computer will continually shutdown/turn on indefinitely and give you no beeps. Strange behaviour, but that we go. The computer lives!

So if anyone else has the same problem, try new RAM!