How to detect only if back button is pressed?

When I pressed my computer's power button nothing happens.?

• I plugged in my computer then, press the power button but it doesn't turn on. I check the light at the back of my CPU indicating that there's an electricity. No Fan activites, hard disk not running, I cant actually hear any sound, but the Light at the back of my CPU is working. I waited for a minute then I pressed the power button a couple of times then it turned on but the Hard Disk and The Fans Are not yet running, then I waited 10 min then it Runs. What is this Problem? I can actually use it but when I turn on my computer the Power Button does not respond, and after I waited 5 min then press it again it turned on but the Fan and Hard Disk is not running then I waited several minutes then it runs Perfectly. I don't think this is a common problem, Is my CMOS battery Low or do I need to Unplug and Plug in its Components?

• Answer:

  Don't you see the problem is out of over heating ? please detach all the cables, remove the processor, fan, heatsink ,even the heatsink of the graphic card.clean through sutable blower,clean with propyl alcohol,apply good thermal paste onto the processor, fix the sink and the fan, attach all the cables and try again. If the problem still persists, your smps fan is out of order. change the smps instead of going for repair. do you use original fan on the processor ? If not, use original one or the branded cooling fans from reputed companies example cooler master. use corsiar,coolermaster,vip,gigabyte,tagan etc smps I clearly see it as the problem of heat in processor due to cheap or insufficient fan or in SMPS due to fan failure.clean your smps as well with smooth brush after opening the case(if it is of cheap one and out of warranty) and clean all the cluster inside and check if any hairs are stuck at rotational area ,drop a single drop of lubricant oil in smps fan at proper junction of rotation.(only one drop) Your smps fan might have stucked due to dust resulting in insufficient rpm thus failing in cooing the smps there by overloading and resulting in failure in release of 5v+ to intiate the motherboard. since there is intiative after few minutes the problem could as well be with the processor heat due to the fan used over processor. It is just overheating problem which require some cooling techinic. If we use cheap fans over processors or use cheap PSU's there always arise the problem of such kind in peak summers. Ensure proper earthing to your system to avoid any fluxes. It is just a over heating problem but need to dig out the resource point and find the solution.