gtx 970 GTX 970 black screening, any ideas?

[driacon]

Hi guys, first post on here so might not be in the correct place.

I bought a PNY GTX 970 for $50 shipped that the seller said worked fine in one PC but when they put it in their new system it didn't give any output. Figured it was a simple problem to fix and that maybe the PC just didn't recognize the GPU.
I popped it into my PC to test and at first it didn't give any signal. Reseated the two six pin power connectors and it gave an output when starting the PC, SUCCESS!  Installed the drivers and it seemed to work fine, downloaded userbenchmark and it black screened...  it wouldn't give an output after that so I let the PC sit over night with the PSU switched off, and then it would give a signal. Sometimes "all the way into windows" but most often it would black screen on boot...  I have bought a HP Z220, not delivered yet, that I was planning on putting a GPU in and flip.

My first thought was that the GPU bios maybe is a bit corrupted? But my motherboard doesn't have a video out so I can't try to reflash it rn. And if a bios flash doesn't fix it what should I do? Is there any way to pass the signal through a different GPU, think the Z220 had a quadro k600, or the mobo? The Z220 has a Xeon in it so I need to replace it with a i series with integrated graphics if trying to pass it through the mobo?

 

I am in no* way an expert but I've always liked to tinker with stuff so any advice is good advice.  Can always sell the GPU and buy a new one but that wouldn't be as fun .