I have an HP media ctr system that is now "unable to boot". System is BOOTED and then shuts down after 30 seconds or so giving me a "cpu fan failure, system is shutting down" message. The cpu is cooled by a passive heatsink and all other fans work. Upon reboot, the system shuts down after a few seconds which leads me to think it's a heat problem. I replaced the stock m-board with the same board (Asus stingray). I borrowed a working chip to go along with the new m-board and same thing. I'm thinking it's the powersupply even tho I'm getting a green light on the powersupply. I was able to check the bios and noted that CPU Fan faliure check was not selected. I'm at my wits end here so any help is greatly appriciated.

Note:
I reset the bios and removed the BATTERY on the stock m-board as well, with the same results.

Nothing new done to the systemm no new hardware or software. It's a 3 YEAR old system, which up until the problem was pretty darn stable RUNNING Media ctr 05. I unplugged everything except the nic, TV tuner card and video card (no HD, DVD, CD, card reader).Green light does not mean the PSU is good. I am amazaed that an HP "Media Center" does not have a fan on the CPU, but uses only passive cooling. Are you sure about that? What processor is involved? Is that a proprietary power supply?Proprprietary power supply It is an Antec board so i talked to them and they as well as HP informed me that it was not "standard". And YES believe it or not it is a passive cooler. I've removed it and will replace it with a fan/heatsink. CPU is a P4 2.4 HT. I'm going to replace the power supply and see what happens.Keep us posted.