Computer won't turn on...sometimes

No help ?

I also suffering the same problem. My processor is Intel dual core and Gigabyte Motherboard. I change almost everything's (Processor, ram, Hdd, Smps, power Cable). But problem is same. i think its a Motherboard Problem. Repair or change your MotherBoard.

When you turn it on. Even though you see nothing on monitor. Does the case fans, that are hooked directly to the PSU work?

If they do. Then Id say it was the motherboard.
If they dont. Then Id take apart my case switch(the on button) see if a wire is loose. On both ends.
Then it could also be the PSU going out.

But i find it hard to believe. That if the motherboard or psu was faulty. That the computer would eventually run, for hours on end. Without a hiccup.
So i feel its the button.
How about trying to do a reset thru windows. Like instead of "shutdown" pick "restart". If it restarts fine, everytime like that. Then Id lean heavily on the button malfunctioning.

Only 1st time it take time. After 1st time open, i can 'shutdown','restart' or 'Re-Open' again normally.

In Hot Weather, 1st time it take 1-3 mints. but in cold weather, even low temp of AC it take 5-15 mints.

I replace my old Cabinet with new one 'Cooler Master'. I directly short the power section with screwdriver, but result is same.

In this case, I think, it's Motherboard Problem.

Which portion of the motherboard is dam, i have no Ida.

If u know, please help me.

Well how cold is it in your house? If you have a laptop outside in around 10degrees F. Then most times it wont boot immediately. If it does, it acts slow.

Other electronics do the same thing. Especially with screens. Just acts funny. Till it warms up.

But i feel its the motherboard.
Id disconnect everything cept for CPU, 1 stick of ram, if you have onboard video, id use that, or use your videocard. Then see if it does it.

But your problem is a weird one, indeed.

Far as identifying whats exactly wrong on the motherboard. Theres really no point in doin that. If its not something you add to the motherboard(like video card/cpu and such)
Computer technicians do not actually fix computer hardware. They isolate identify and replace the part. Which would be the motherboard. Once they were for sure.

But im not sure in your case. Would have to be something, i have hands on with. To rule out.

You could of course. Buy a compatible motherboard. From a local store. Then see if it works. Just make sure you check the return policy of store. If it works then great. If you want a better or cheaper mobo. Then return it anyway.
Then buy one online. If it doesnt work. Then you know its not the motherboard, then return it.
Make sure you ask and know the return policy, of the store for the specific item! not just the return policy in general.