System not starting LED on mobo is on

[aura]

hello members, Asus P5KPL-CM , led is on (green) but when i press power button doesn't happen anything...i directly shorted the pins on mobo and nothing happened....something happened yesterday ..and after an hour of headbanging it started working...(I didn't do anything ) right now i have pulled out mobo and tried starting it..nothing happened....what could be the problem? tried with diff. PSU, even though current one is fine... any suggestions? I had powered off system yesterday, was working flawlessly....

 

[Voodoo]

Processor fan is working?
Processor 4 pin power connector is connected properly?
Reinstall Rams, Reset Bios using the Jumper,

 

[Cerberus]

Processor fan is working?
Processor 4 pin power connector is connected properly?
Reinstall Rams, Reset Bios using the Jumper,

+1....also re set processor

 

[Alcadeias]

Re-attach all psu connectors and re-connect RAM then try .

 

[Newton]

Processor fan is working?
Processor 4 pin power connector is connected properly?
Reinstall Rams, Reset Bios using the Jumper,

even if those things are not working fine it should power up on shorting the mobo power up pins, right?.
either you are not shorting the proper pins or you're not shorting it with a conductor. and if the shorting is ok, then check the 24pic psu connector on ur mobo, is it properly pressed and connected......clean it well the connector on the psu and the mobo and reconnect.
if this doesnt work then we can figure out something else.

 

[Alcadeias]

Without processor 4 pin connector the motherboard will not run. I myself have tested this on a Pentium 4 .

 

[AliMan]

Your Mobo's Fried.....Check the North Bridge chip...

 

[amjad635]

looks to me mobo problem

 

[Solid snake]

Bro if ur cpu fan runs when u power on then first of all u have to check that ur rams and cpu working properly or not..to check this first connect speaker on ur mobo which is included with ur mobo's accrs or casing accrs..
Then remove ur rams and power on if no beep comes then its means that cpu not working if beep comes then its means ur cpu is working properly and there is some prob with ur rams...then try to clean ur rams and rams slots...if still there is no display then try to get ram from ur frnd and check if still not then check by changing gpu..if still not then ur mobo's fried.hope it helps..

 

[aura]

let me rephrase..when I power on (switch on the casing) what all of u have suggested would have been plausible provided if system was starting up i.e. CPU fan spinning , etc etc ...their woudl have been beeping...heck I would have pulled out the RAM to check if mobo was fine or not....but this is not the case.....after pressing the power buttton on PSU..the green LED lights up...after I press power button nothing happens..no response....
and right now it started and am posting using the copm. temps. etc etc are prefectly fine......but I'm sure tomorrow morning I'll have same problem.,...today was second day

P.S. shorting the green and black wire on 24 pin PSU connector, CPU fan starts working, mouse/keyboard get power too....but nothing happens

 

[AliMan]

Man you really aren't explaining your situation properly.....Do you power the system using the Casings Power Button? so whats with the Power Button on the PSU? or are you talking about the ON/OFF switch?
Try not shorting anything with your PSU or you'll fry it completely

If you've even tried it with a different PSU then check if your Power Button is functioning correctly by directly starting it from the Mobo itself...

 

[aura]

^
here is what is happening:
Power cord of PSU is plugged...LED on mobo turns on indicating power to system.
when I press power button on casing, system doesn't start. (In other words after PSU is powered on, but system doesn't start if power button on casing is pressed)

regarding checking the casing's power button, i directly shorted the pins on mobo but nothing happened.

I hope I clear now, what problem I'm facing......

this is why I'm baffled as well...clearly the signal generated by pressing the power button casing isn't doing anything....
once however system is started it works flawlessly i.e. I can hold on the power button for few secs. system turns off....press again and it starts up....