u/DolphinToucherr

I built my PC in January and everything was fine then all of a sudden my BACK FAN stopped spinning on 30% of the time when turning the pc on but would either start spinning after rebooting or 10/15mins into usage. Now, neither my front fans or back fan start on boot (50% of the time) and after using the pc for 10/15 mins, my middle front fan turns on, then my back one and then the other 2 front fans. I can see that Sys_fan 1 2 and 3 are all being used as well as cpu_fan. Any ideas on what this could be?