New computer has serious problems - any ideas tonight (Friday) - help! (Ref 366247)

[Growltiger]

*** EDITED - the machine is being shipped back to PCS - the reason for the problems is unclear, perhaps the motherboard is soaking up power. ***
*** So suggestions no longer needed, thanks. ***

I'm beginning to despair, my new computer has a serious and puzzling problem. I'll be phoning PCS yet again in the morning, but it would be interesting to see if anyone has any bright ideas.

It is an i7 950, Titan Fenrir cooler, 12GB memory, nVidia GTX 460, 850W power supply.

It all arrived working fine, except that that the CPU seemed too hot to me, idle 51, and running prime 95, 97 degrees. No overclocking, so 3.2GHz. (It also lost its CMOS settings almost at once.)

In contrast a very similar home built i7 920, overclocked to 3.48GHz runs at idle 44, and flat out with prime 95, 80 degrees.

I phoned and was advised to reseat the cooler, I did this and it made no difference. But the machine then lost its CMOS settings again. After unplugging/plugging in, it then refused to boot (no beeps at all). PCS support were very helpful, talking me through taking out memory, battery and graphics card, and this got it beeping again, and it booted.

I was advised to test for bad memory, using one stick at a time. But now the machine got worse. Even with no battery and no memory, it doesn't get through POST, no beeps at all.

At this point I had an idea. I removed the video card and at once it would start up and beep. So I plugged in all the memory, and the battery, and an old slow ATI X1300 video card, and guess what, the machine works perfectly. Never loses its CMOS settings, even on unplugging, always boots, all the memory is fine. Still too hot in my opinion.

So I phoned PCS and suggested the GTX 460 could be faulty. They swapped it (I had to drive through the snow as DHL were not going to deliver), and I just installed the brand new GTX 460. Machine immediately went dead again. Wouldn't boot, no beeps.

I put back in the ATI card, all OK again, except the CMOS wiped again.

So - we are pretty sure the GTX 460 is not the problem after all, and we know the memory works OK. So logically it must be the 850W power supply or the CPU/motherboard. But neither seems likely.

By now I have rebooted this machine about 70 times and I'm rather sad about it all. It seems bad that I can't run the 950 as fast as the 920, because of the heat problem. And the mysterious failure to get through the POST is very puzzling.

I'm happy to try swapping the power supply or indeed anything (I've built machines and never had a problem), but I suspect PCS will be coming to the conclusion that the whole box will have to be shipped back.

So does anyone reading this have any suggestions about the saga of my new machine?

 

[Craig]

Don't understand how it could be the PSU - you either have power or you dont. Is the power plug pushed all the way into the socket on the wall? I doubt it but it can happen.

Does sound like something is faulty, maybe even the cpu chip. best bet would be to send it back. it must have got damaged in transit.

 

[Growltiger]

I have power. The two lights at the bottom of the motherboard and the red one next to the memory which should go out. And the fans all spin. But it fails POST, no beeps at all, if the GTX 460 is plugged in. Remember it used to work when it first arrived (for a few hours), then it seemed to go steadily downhill. Removing and replacing the battery would get it going, then nothing would make it go except removing the video card.

I was clutching at straws but the GTX 460 must use far more power than the old ATI card. So my idea was that the voltage was dropping under load to the point where it was inadequate. A faulty supply could in theory do this.

What do you think about the heating issue?

 

[Craig]

Heating issue, well it is pretty hot, so I think something isn't working, could be a faulty fenrir but I doubt it. Depends on the kind of room you are in though and what the temperature is like.
Still think it should be about the same as your 920 heatwise, or less.

If everything works fine with the ATI card then it does sound like its the GTX 460 having problems. PSU could be an issue, but who knows.

 

[Growltiger]

It is very puzzling. There is nothing in a Fenrir to go wrong - the fan works fine. The room is not hot. It isn't the case, it is the same with the case open.
Replacing the GTX 460 made no difference, so it isn't that.