My back fan has been having issues lately I got it replaced with a new one thinking that would fix it but it is doing the same thing and will turn on sometimes right after I turn on the computer or might not turn on at all and I cant figure out why any help would be very appreciated.
Is it plugged into the motherboard? Could possibly be a bad fan header. Have you tried any of the other fan headers if any are available?
If all the other fan headers are used you could try something like a molex fan adapter assuming your power supply has a molex cable that's not in use. That should make the fan run as its pulling the power directly from the power supply instead of through the motherboard
How is the fan connected to the system? Make and model of the fan that you have inside the case to replace the older fan? In either case, please mention the make and model of your PSU(if it's hooked to the PSU) and the make and model of the motherboard(if the fan is hooked to the board).