I just got equipment for 2 mining rigs yesterday evening. Used some time to mock up my first setup to play around with. The systems are build up of 12x Sapphire RX470 Nitro+ OC 4GB, 2x ASRock H81 Pro BTC, 4x CoolerMaster G750M....
More about the system here:
Now the problem is that the mainboard won't POST, well sometimes!? I stripped the setup down again to the mainboard and 1 RAM stick, that's it. Then I got into the BIOS. I updated the BIOS to the latest version, enabled internal GPU as primary device and enabled Multi GPU.
The board did restart normally. Then I installed one GPU after another, testing the board after each card. But sometimes the screen just stayed black, even without adding or removing a GPU. After a few resets and power-offs and -ons it would boot with all 6 GPUs. So I was able to install Xubuntu 16.04 followed by a few restarts, and compile zogminer.
After another restart the screen stayed black again. No POST what so ever.
So I removed all GPUs again, but no POST. After a CMOS clear it started again. But as soon as I used just 1 GPU the board didn't post again. After another few resets and power-offs and -ons it started again. But I had to restart the machine again after installing the AMD SDK. And the screen didn't turn on another time. And now my reset & power-off/on trick won't work anymore.
Any ideas on that or how to troubleshoot? Did not have time yet to check the 2nd board. Will give that a try later today.