You may have left out that it works when it cools off. But to test the PSU is pretty trivial. Google this: "Green Wire PSU Test." I don't know your tech skills but since most want to know it's this or that, that's the test I would use next.
Hi .. I will get straight to the point .. I was running my desktop computer the it suddenly shuts down and when i tried to turn it back on it it don't but it seem he have electricity ... I have searched and i found it maybe a power supply problem .. How can i make sure of that and if it's true can i fix it by myself ?!Thanks ..