The case has 3 fans, one at the rear, one at the top and one at the front. The one at the front and top run fine but the one at the back isn't spinning at all but the the LED on the fan is working fine. What is wrong here?
Also, the fans arn't connected to the motherboard at all, it appears they are all linked together and i'm given like 3 or 4 Molex cables to connect up at the bottom. Is this a normal thing that case manufactuers do? In the bios it also says the chassis fans are N/A (0RPM) But two/three are spinning, is this because they arn't directly connected to the MB?
I found another female molex round the back of the case after searching online, the fan now spins. It still doesn't explain why the bios says there are no chassis fans spinning though.
Yes it does, you answered your own question. You have the fans plugged into to Molex connections. The BIOS can only read fan rpm when it gets that feedback from the 3rd wire when it's plugged into the MoBo Chassis fan headers. The bIOS can not read a signal that the MoBo doesn't get and since you powering the fans via the PSU molex connections, it doesn't get that signal.