Symptoms of a bad motherboard?

[BlueHornet]

So I put my new system together today, following the manuals for the motherboard and the CPU in the installation. I got everything installed, but the system won't POST. The power comes on, the fans start (and the variable speed control works), all the "Phase" lights illuminate initially but then go out after 20 seconds or so...but I get nothing on the screen. It will run until I turn it off, and the reset button does cause it to reset; and then actually reset again after about 15-20 seconds for some reason. But then it restarts and continues to run, without resetting again. I checked and verified the correct wiring (and unplugged the harnesses and plugged them in again) three times--and I even removed the 6850 video card and tried using the on-board HDMI port. The thing doesn't even give me a beep or fire up the BIOS. I get nothing on the screen whatsoever. I've tried all the RAM sticks individually, in the slots recommended in the manual, but it doesn't make any difference. The monitor works on my other machine, so it's not that.

Reasoning that I must have screwed something up, I removed the CPU cooler (Hyper212 Evo), and unseated the CPU. I had applied a bit too much heat sink compound, as it had just run off the edge of the CPU's surface--but it didn't get anywhere near the edge of the chip, or the socket itself. But I cleaned it all off, and applied less on the next install. The CPU went into the socket just fine as well. But even after all of that, nothing changes--fans still work, phase lights illuminate and then go out, and the machine continues to run and run and run...but nothing else happens. The HDD spins up, and the optical drives both have power.

So other than two sticks of RAM and some SATA drives, I've got nothing else installed--and I still can't get it to POST. I've heard a couple stories about bad Gigabyte boards, but I've never experienced this myself...so could this be I've got going on? I've been Googling around a bit, but haven't yet found anything definite.

Anyone have any ideas?

TB

 

[samisnake]

take the board out of the case, and place it on the box.
use the minimum needed to start the system- one stick of ram, no hard drives/dvd drives, all power cables plugged in.

hopefully its just a simple short with the case mounts or something.
however its possible you have a DOA board, which does happen. in which case youd have to rma the board

 

[Jerime]

It sounds to me like the CPU is bad, not the motherboard.

 

[eirrann]

I'm experiencing almost exactly the same thing.

Going to take CPU, mobo, ram and gfx back to the store to let them troubleshoot.

I'll be curious to know if you work out what's the cause.

 

[BlueHornet]

Apparently none of it is bad, because it now works!

There were two problems...one was the real issue, but one was created by me trying to troubleshoot the main issue:

1) I don't know for sure what the first problem was, but I'll get to that in a minute.

2) The on-board video, by default, is apparently disabled on this board. I didn't see it in the motherboard manual, and I read the section on the HDMI port a couple times--but I'll have to look again today. But it didn't work, even with the 6850 card out of the system. I would have thought that it would have been enabled without the GPU installed, but I guess not. So I think this was the "problem" I created, simply because I missed it where the manual states that the on-board port needs to be enabled in the BIOS or something like that.

As far the first problem goes (whatever that was), this is apparently the only problem that existed. So it seems that I was going in the wrong direction when I removed the 6850 card from the PCIe slot, and used the on-board HDMI port! I even removed and replaced the 6850 at first but it didn't make any difference, so I removed it from the system to look elsewhere. But in hindsight, I think the problem may have in fact been the power plug connection on the 6850.

For background information, I installed the card in the PCIe slot nearest the PSU, towards the bottom of the case. Here it covers the adjacent PCI slot, instead of the PCIe x1 slot adjacent to the other PCIe video slot. Therefore the cooling fans are not easy to see when the machine is sitting upright. Although I could swear the fans were turning when I first tried the machine, I guess I cannot be 100% certain at this point. They are extremely quite, and any noise from them is easily masked by the cooling fans on the case. But when I removed the board and ran it on the box per samisnake's recommendation, I could of course see the card much better; and the GPU fans weren't turning at first! So I removed and replaced the power plug a few times, as it was VERY snug. And all of a sudden the fans came on, the machine went to POST, and I could enter the BIOS!

So then I reassembled the machine, installed all the RAM and reconnected all drives...and it still works! I guess it was probably the plug on the 6850, but I cannot be entirely sure--other than to suggest that if it took 3-4 attempts to be certain that the card's plug was seated properly when the mobo was on the box, then in all likelihood I it was not properly seated at first when the board was in the case. It's the only explanation I can offer, because the machine now seems to work just fine. I'll install Ubuntu today, on the 90gb SSD. If everything still seems OkeeDokee, then I'll go for the Lion installation. I suppose there certainly could be some other problem that just hasn't reappeared just yet (but will), but for now everything seems normal.

Very weird though, but samisnake's idea is what seems to have resolved the issue for now, so THANKS for the post!

TB

 

[eirrann]

Hmmm. I've torn my machine down and put back together a couple times now (the third time with a friend who has built PCs before), checked and rechecked all plugs, and breadboxed the thing. No change in reaction any time. Thanks for the info, glad your machine now works!

 

[Gordo74]

If the Phase LEDs go out, it is POSTing

 

[eirrann]

On my build, phase leds stay on
Top is red, next is yellow, bottom two are green.

 

[Gordo74]

I know that. Let's keep your problem to your thread

 

[eirrann]

My bad.