Won't boot with GPU installed

[key00]

I have a LTC rig set up with the specs below.

MB: MSI|970A-G43
GPU: 2x SAPPHIRE|100352-3L HD7950, 1x RMA
PSU: CoolerMaster 1000w 80 PLUS Gold
CPU: AMD|SEM 145 2.8G AM3 R

It spontaneously shut down and now it will only run with one of the cards installed. With the other card plugged in the machine will not boot, no lights no fans nothing.

-the riser cable that was on the "bad" card works with the good card
-the good card works in every PCIE slot
-the PCIE connectors from the PSU work with the good card

This whole set-up is roughly two weeks old. The cards don't reach over 70 degrees C and I have never seen any hardware errors in cgminer. This same problem happened to me about a week ago with another video card so I sent it in for return.

Is this really a GPU problem? Or is it a PSU/MB issue?

Thanks in advance for any help, been a rough start to mining...

[brooklynite]

I have had similar problems. I went through every possible thing that could go wrong. Three motherboards did similar stuff, lighting up and not booting, or not even lighting up all on their own. One Sapphire 7970 card that was 1 week old just stopped working on me, I shouldve sent it for warranty instead of returning it to Amazon because I had got a bargain $299 on that.

When I saw the thread I thought it may be a power issue but with 1000W you dont have that problem.

Try a new PSU. I think you have a power issue or short, thats when computer would not turn on at all because PSU wont supply power if there is a short (or overload, same thing). I had a Rosewill 1000W PSU burn out and computer would not start at all. 3 motherboards burnt out back to back finally I got luck with a really low quality bad reputation $80 MSI MB but only has 4 PCIE slots.

[hostmaster]

i suspect from power supply... Or update mainboard bios.

[JL0z]

Could be power supply.  Swap it with any other power supply, leave one gpu installed, it should be able to boot and stay up.  If you want to mine, the psu must have sufficient capacity.

I got up this morning to find one miner powered off.  Would not power on.  Turned off the power board, then waited a while and turned on.  The machine would start up, then before it finished booting - powered off again.  I started taking out gpu's and even with one gpu - it would power off in the middle of boot, so it must be a bad power supply.  Rang up the shop and they said bring it in (3 weeks old unit).  Tested with my psu tester which showed -12V was high (meaning not there perhaps).  Took it back and waiting on a replacement.