Hello

So I just bought a new 1070, bringing my total up to 4.
I plugged the new one in and all was good for 5 hours, then before bed I checked it and it had frozen.
I down clocked the memory a little and 're booted, now all I get is a black empty box which is claymore on a black screen. I 're boot but get the same blackness.
I tried resetting the cmos but no change I also unplugged the new card but no change.
Any help would be greatly appreciated.

Cheers