Long story: * Brand spaking new home theatre setup - asrock 775dualvsta motherboard, p4 3.2 cpu, 1gb ddr, 430w coolermaster psu. Put it all together with no problems. * Plugged it in, booted up, looking good. Turned off after a couple of minutes. So I took it all out and put it back together again. This time it lasted half way through the OS install before it turned off. * So I go into the bios and realise that *SOMETIMES* the CPU fan doesn't turn on. I do the usual - reseat the 4-pin cable, redo the thermal paste, put it all back together so carefully. And it all worked beautifully for a good week or so. * But today its doing the same thing again, turns on and the CPU fan works for 10 seconds then stops. I'll leave the system off for an hour, then try again and it'll work for an hour or so then turn itself off! Its very temperamental. Before I rush out and buy a new CPU heat sink and fan, I just wanted to see if anybody else had any other ideas? Is it possible I'll have the same problem (i.e could it be the 4-pin connector on the motherboard?!). Any suggestions would be appreciated! I'd really just like to enjoy my new media centre before the technology is end of life!