Computer sutdowns after few seconds of turn on

This could be due to high CPU temperature, you use a cooler for disipation of HEAT in CPU, and between the CPU and Cooler, there is a termal paste for a good heating disipation bewteen the cooler and the CPU, so if you had your CPU with that termal paste for more than 2 years or more, you will have to change it, because your CPU goes to more than 90 Cº and it automatically shutdowns for preventing damage.

If this is not your case, you must tell me, what happend, after it went off, if you try to turn it on. If you cant turn it on for 5 minutes, is that, if you cant for more than 10 minutes, maybe the power supply is in bad health.

Try that, and tell me, I will advance :)

Good luck.

P.S.: Sorry for my non technical english :P

Thanks for the reply i will try it and write back you soon :)

I'll be waiting :)

I would be quite surprised if this was a problem with the CPU overheating. As far as I know (and I'm not an expert), a CPU cannot overheat that fast (few minutes), unless there is significant and visible damage of the thermal paste or a nearby burned circuit. If you have a burned circuit or chip, it would be visible as a burn mark (usually around the "legs" of the chips), and would also have the very distinctive smells of burnt silicon and/or burnt cardboard (from PCB) which is hard to miss (believe me).

And also, thermal paste can lose its efficacy over time, but it is rare that it would just disappear overnight (or even in a few months), unless there was significant tempering (messing with it).

My bet is on the power supply. This is a common "cheap component" in many computers, i.e., the computer sellers often cut cost by putting in very cheap power supplies that barely meet the power requirements of your components (especially if you upgraded something), causing them to fail early. And the kind of failure you describe is very typical of a power supply failure. They often fail by being able to provide some power for a short while, until the demand is too great and they crumble, causing the computer to just shutdown as if there was a power outage. Diagnosing it is a bit harder without equipment (you could open it up and check for burn marks, or you could take it out of the computer, then power it on, and look for an odd smell or unusual heat). In any case, power supplies are not very expensive, and getting a new (proper quality) power supply is always a good investment, even if that turns out not to be the issue.

I would try checking the power supply before I would try to mess with the CPU heat sink (which is a very delicate task).

Unplug the power cord to the laptop. Remove battery. Hold the power button down for 60 seconds and release. Without re inserting the battery, plug the power cord, and boot up. This will isolate if it's a bad battery or not.

I don't think the OP is talking about a laptop here. I'm pretty sure this is about a desktop computer, given the references to cleaning the motherboard, and having an "external graphics card".

We can not help him until he answer my question I asked first: "You must tell us, what happend, after it went off, if you try to turn it on."

Anwser this please...

Sorry for the late reply guys. i tried with the thermal paste as your suggestion. It is still shutting down after turning it within a minute.

no i will try as mike suggested me.

and reply all of you soon.

thanks for the suggesstion guys.

Bejea, first of all... why another user ? second, i will quote it again...

You must tell me, what happend, after it went off, if you try to turn it on.

I turn it on, then after some time within 1 -2 min, it shutdowns automatically. and i again had to turn it on. This is repeating again and again.

So, the problem is the power supply... can you tell us which one you have ?

i just know the company, and its JDkee, or how should i say it, is it on the basis of some elements over it, or what?

Hey guys, i try by changing the new power supply but it didnt work. The problem is still the same. on it after a while it shutdowns and shows start computer normally or repair.....
Can somebody help me?

mmmm.... maybe is your hard drive... do you have other hard drive to test ?