As always, one of my rigs started to act up whilst I was on holiday. One GPU would start showing 511C errors, crash the miner and the rig within a few sec. Seeing that this couldn't be fixed remotely I cut the power to that rig completely using the tp-link smart plug app and decided to address it when I got back.
It was quite an easy diagnostic:
https://[Suspicious link removed]/p/ETFBZz
Flimsy Chinese risers. Always make sure you got a few spares, and don't insist on powering up a failing rig remotely if you suspect there's a hardware/power error.
Always use MOLEX powered cables to avoid fire

6 pin to SATA is fine too, right?
no never use anything with fucking sata to power risers. in worst case you will destroy your gpu or burn your home
RIP me, since my psu only has 2 pci ports and they are being used for cards. My risers have a 6 pin port, sata port, and a 4 pin port. I just used the 6 pin out of the back. I also use the 6 pin to sata since thats what came with the riser, so I guessed that is how it was meant to be used.