Yes, That's not the problem. According to the Service Manual for the motherboard there's a fan mounted at the back of the case that they call the "System Fan". That fan connects to a point on the motherboard between the CPU and the rear of the case. Just behind the HDD, on the motherboard, is a point with three pins that the Service Manual says,
Originally Posted by Temüjin
I used to do maintenance on a bunch of PCs for a school, and some of them had this feature, most did not. Usually when we bought new power supplies they did not have this "System Fan power connector" and I used to just ignore them, never had a heating problem but we're talking ten years ago and more.
8. Connect the System Fan power connector to the MB connector.