Recently installed a EVGA BQ 850 power supply in a friend's system to replace a failed power supply he previously had (was the same wattage but from corsair), but while the power supply seems to be working as in the main hard drive (an SSD), his video card, ram, motherboard as well as the fans for his liquid pump all all working and all, but i've been unable to get the spare hard drives and fans on his case to work with this new power supply. I've tried plugging the case fans into the perif sockets via both the original modular cable and when that failed to work tried the cable that was provided and still nothing. Same with the cable that connects to the spare hard drives. Both modular cables they were firmly in the sockets and the drives and fans were securely plugged into their respective ends but still no go. I know for a fact that the drives themselves work since they all worked with the old psu and tried them in other systems. Tried checking the Windows DiskMGR and Bios but they don't show up at all. So i'm kinda wondering what to try now?
Windows 10
Intel i7 6700K
ASRock Z270 Extreme 4
48GB Ram
Evga BQ 850 PSU
XFX RX 480 Video card