Rig stopped seeing any vga card

[Bitblockchain]

A little prehistory.
Hardware:
Gigabyte H110m-D3A, bois 23, CPU is G3900, ram 4 gb. Windows 10 64 bit. PSU is 500W corsair and server power supply 1200W.
Running 2 R9 280X for 3 weeks.
Suddenly the rig started to restart and i found that the PSU is the problem.
I bougth fortron he-500. I connect the psu to mainboard and cpu and hdd and one R9 280X. The windows did not detect anything in device manager. Any of the cards. I bougth 4 more R9 280X. /My plan was to use 6 vga card on the same board/
What i tryed:
- BOIS restore, flash to latest and many bois setting variants - not detected any card
- Fresh install of Windows to other hdd - not detected any card
- install of different AMD drivers 15.20,15.7,16,17 and uninstall every time with DDU - not detected any card
- try to plug any of the 6 gpu card in pcie16 line - not detected any card

I need help on troubleshooting. Can`t imagine what else to test.
Thank you for the support!

[dagarair]

if you tried plugging on board direct and you FOR SURE reloaded windows from scratch then your pci16 slot is probably bad.

[Bitblockchain]

Yes, i install fresh win 10. Also tryed with risers , same not detect effect.

[baga105]

Is your psu burned? Check the 24 pin..

[Tristan1337]

Since you already tried another PSU and it didn't work. It sounds like you might have fried your motherboard.

Maybe time to buy another one unfortunately.