Hi have recently built a new PC about 3 weeks ago, the specs are Intel i5-2500k @3.3ghz (standard heatsink and fan are being used to cool this), Asus P8P67 motherboard, 4GB DDR3 kingston hyper-x (KHX1600C9D3K2/4G), Cooler master 650w that runs the CPU with a 4-pin power connector not 8 as the psu is about 2-3 years old but fully functional, nvidia 8800gts and a seagate 500gb hard drive.
My problem is that when i power on the pc, it does not display anything, and no beeps occur, then after exactly 5 seconds it turns off then turns on again, and when it turns on again it boots into windows normally going past the POST and the beeps with display etc. as someone else has asked Why does it restart itself after these few seconds and continuous to run? i have not updated bios or anything and i have tried this with 1 stick of ram which is placed in the correct DIMM slot as the motherboard manual recommends, i have also tried using my bro's Cooler master GX 750W psu which has an 8-pin connector for the cpu, but still i have exactly the same problem.
The mobo is auto overclocking. Mine does it every time. EZ mode is set to more performance, therefore every time you start the pc it will overclock, when the mobo set up the required volts it will restart. Also if the TPC swithc on the mobo is on it will overclock automatically without going to the bios.
Trust me, mine does it because is set to max performance on the bios. When I set it to normal, it did it a couple more times and then stops. If theres any other reason for it to do this then I dont know it. Its kind of annoying but I grew used to it.