Question ASUS B250 Mining Expert | No Bios - Boots to black screen with cursor, no signal after CMOS reset

Oct 21, 2019
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I’ve got a problem with my Asus B250 motherboard. I had a previous board that worked flawlessly with 9 cards for 3 months. I moved the rig recently and it fried the mobo when I hooked it back up... Anyway I’ve ordered a new one and I was initially having problems with some of the GPUs booting normally but others where the fans just keep spinning which is usually a riser issue. I decided to go from 4 PSU to 3 PSU in case it was an issue there with power balance etc. Still no luck. Last night I managed to get everything hooked up nicely and it seemed to like it to begin with but it booted to a black screen with cursor in top left corner. I reset by removing battery, turned on and now it gives me nothing on screen. Fans and CPU appear to be on but just nothing...


As a sidenote, i've already returned the new board for a second new one and the same issues, so ruling out the mobo being the problem.

Heres my setup;

1000W EVGA PSU – CPU, SSD, 3 X Radeon Vii & 1 X Vega 64, risers for these GPUs and molex to PCI ports on board, I know people say you don’t need these with powered risers but when my rig was working it would only boot with these plugged in.

750W EVGA PSU – 2 X Radeon vii and risers

750W EVGA PSU – 3 X Vega 64 and risers

I've tried plugging all PSUs into board and now i've left it how I originally had it with Add2psu from 1000W PSU which is powering the board plugged into 'A'.

Ram – Ballistic 8gb 2666 Mhz


Really appreciate any help, it's driving me insane!
 
Any more than one GPU gives me the black screen with cursor. I've re set settings to default, updated the BIOS to latest firmware and nothing. Tested other GPU/Risers and they work. Tested other slots and they work. I'm baffled...

Could it be the RAM?
 
I've tested moving the risers around to different PSUs, the only thing the other PSUs are doing are sending power to additional PSUs, so don't see why I wouldn't be able to boot up more than 1 from the other. Only thing I can think of that I have changed is that I had power running off A & C on the mobo, C having a daisy chain wire to start additional PSU, now I have 1000W on A and use 2 x add2psu for the other 2. So has to be that... I'll have to wait until I get home tonight to test
 
I've managed to get 6 GPUs working. As soon as I plug in 3rd PSU, which is only powering 2 GPU and nothing else, it goes to black screen with cursor. Tried replacing that PSU, same problem. It sounds like a power balance issue to me, but I have no idea how to fix it...