Can you describe how many watts PSU its?
If there's a problem with his Power Supply, the rig will not boot at all.
But still, there's no harm on telling us your PSU's brand and Power Rating.
Have you tried to reset bios via CMOS?
This is pointless, resetting the Bios doesn't always
magically fix problems.
All GPU's fans are spinning means that the PSU supplied them enough power to start.
Either the PC can't detect the cards due to bad riser cables, PSU cables, bad riser or the problem was caused by claymore miner's settings misconfiguration.
Start by (
any of the two):
- Swapping undetected cards to the working Riser slot and insert the working card to the undetected riser.
- Read claymore's thread and some documentations about it for the proper configuration.