GA-X99-UD5 Won't Boot/Boot Loop

[Sface]

Hi all,

I've just put the following together:

- Intel 5820K 3.30GHz
- Crucial 16GB (4x4GB) DDR4 PC4-17000C16 2133MHz
- Nvidia Geforce 980
- Corsair Builder Series CX 750W Modular '80 Plus Bronze' Power Supply

However I'm having a strange issue that I can't understand. Essentially if I plug both PCI-E auxiliary power cables into the GPU the machine won't boot. The debug LED screen doesn't show anything, the CPU fan doesn't spin up, nothing. However if I unplug on of the cables (only right one, if I remember correctly) then the machine starts to boot. The debug screen shows 60 but after about 10 seconds it powers off and does the same. What's peculiar is that if I remove the GPU completely it doesn't boot at all, and if I power the GPU with another PSU that I know works it also doesn't boot. The GPU works in my old machine.

Here's what I've tried:

- Removing the GPU (Result: doesn't boot)
- Moving the GPU to another slot (Result: doesn't boot)
- Powering with another PSU that works (Result: doesn't boot)
- Removing one PCI-E auxiliary cable (Result: Powers up, no output (obviously), debug code 60, cycles endlessly)
- Remove all RAM to see if MB is DOA (Result: correctly shows error code 50 or 53 (I forget, but both are memory))

Tonight I'm going to try moving the RAM around (I have tried this but not all combinations) and to use only one stick in the correct slot (3rd, I believe). I can't see how this would affect powering on however. To me it seems like a power issue but using the other PSU to power the GPU had no effect, even though I know this PSU works, is exactly the same as the new one, and has been used to power this GPU before (I'm moving the GPU to a new machine with the same PSU).

Has anyone got any other ideas? Is it possible and safe to update the BIOS if I remove one power cable from the GPU to get it to boot? Obviously I can't see how far it's even getting as there's no output. I'm at a bit of a loss and would appreciate any help you guys can give me.

Thanks.

[dmdilks]

Check the CPU socket and see if you have a bent pin. Plus do you have another video card you could try?

[Sface]

OK thanks, I'll check the pins tonight. I'm really hoping I don't have a bent pin 

I do have a GPU I can borrow from work to test with; I'll do so tonight. For what it's worth my friend has the same motherboard and GPU as me but has no issues.

[dmdilks]

The bad thing about all the boards today is that everything runs through your CPU. I would try the card first.

[Sface]

Hi again.

Sorry for the late reply - I got a little bit worse for ware on my birthday

Anyway I have solved the issue. It seems it was the RAM that was the issue. For whatever reason the slots are very temperamental and I had to reseat them multiple times before it would boot. Very strange but it is at least working. Both power sockets and the USB 3 header are also very loose and seem to fall out.... Regardless, I'm happy to have my PC working.

Thanks again for your help; I greatly appreciate your assistance.