Desktop started heating up yesterday. Package measured 100 Celcius. Shuts down before I have a chance to do much in the BIOS. I've removed the water cooler -- first time doing that.Cleaned up old thermal paste and applied new paste -- first time doing that. Looks like this is a 3-pin Corsair, so I believe I cannot use PWM, it must be set to DC. I never knew what to set it to in the BIOS. I'm a software guy. Definitely not into hardware.