This is the hardware I'm using:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Pentium G3220T (Purchased For $79.99)
Motherboard: Biostar Hi-Fi H81S2 ATX LGA1150 Motherboard  ($65.60 @ Amazon)
Memory: G.Skill Ripjaws Series 4GB (2 x 2GB) DDR3-1600 Memory  ($30.87 @ Newegg Marketplace)
Storage: 64GB KingSpec 2.5-inch PATA/IDE SSD Solid State Disk (Purchased For $51.75)
Video Card: MSI Radeon RX 480 8GB ARMOR Video Card  ($244.98 @ Newegg)
Power Supply: EVGA SuperNOVA 1300 G2 1300W 80+ Gold Certified Fully-Modular ATX Power Supply  ($179.99 @ Newegg)
Operating System: Microsoft Windows 10 Pro OEM 64-bit  ($129.95 @ B&H)
Other: PCIE Micro PCI Express 16X Riser Card Flexible Cable Extension Cable  ($6.92 @ Amazon)
Other: PCI-E PCI Express 16X to 1X Riser Card Adapter Extender Flex Flexible Extension Cable  ($15.61 @ Amazon)

For some reason the GPUs are giving me a lot of troubles  . I upgraded the rig from 4 R9 280s to 3 RX 480s and as soon as I swapped the cards everything started crashing. I am trying to run Nicehash miner on it but the whole thing is very unstable.

What's wrong:

• The cards only work in x1 slots, the x16 slot doesn't even give an output
• Windows says the x16 slot has an device error 12, I looked it up and it seems the device is conflicting with the onboard audio, but the conflict persists despite my disabling the audio device in windows
• The GPUs throw a VIDEO_TDR_ERROR bluescreen regularly when run in the x1 slots
• The miners (normally Claymore's ZCash Miner) crash with the error "GPUx Hangs on OpenCL Call, exiting" or "GPU x,  GpuMiner kx(x) failed -36"

What I've tried:

• Turning it off and back on
• Reinstalling drivers, currently running latest AMD drivers
• Reinstalling Windows
• Running Linux (still got GPU errors)
• Testing each GPU individually (did have a bad one which is why I currently have 3, but still getting errors)
• Testing with different risers
• Windows device troubleshooting

I'm not sure what to try next. Anybody know what could be causing this?