This worked for me for the RX 570 fan not spinning. My computer is an AMD FX-8150 on a Gigabyte GA990-FX-UD3 (ver1.1) motherboard. GPU is MSI Armor AMD RX 570 8 GB. When my 16GB (Timetec 16 BG kit) ram was set at 1.5 V in the bios my computer would crash and I would notice that the GPU fans would not spin (if they spun at the boot, they would stop spinning right afterwards). After thoroughly cleaning the GPU and repasting the Dual cooler, it would still crash. The only solution left for me was to lower the voltage of the RAM to 1.3 V and now the GPU fan spins and there are no crashes. How weird is that? Hope this works for anyone who is experiencing Fan and GPU problems. You may have to play with the RAM voltages based on your RAM type and Manufacturer specs. Good luck.