Failure of power supply on newly built PC

I have recently built a computer and that was running fine for one week but now I am facing some problem with that. Actually whenever I try to start the computer then after 2-3 seconds it get turned off automatically and I cannot see anything on the screen. It is also not giving me any beep sound or any kind of indication that what is the issue. I have not seen anything like this before. I consider that this is the problem with the power supply but I am not very sure about this. Can you please tell me that how can I get out of the issue?

Which PSU are you having in your computer? I think that you are correct that this is the problem with the power supply. My suggestion to you is to unplug the 20/24 pin connections that is there on your motherboard and after that connect it properly again. I am saying this because it is possible that the connection is losing and so it is cutting the power supply to the motherboard. This is one of the most possible reasons and the solution for that.

This is definitely the power supply problem. So try to do the suggestion given above and see if that is helping you. If that cannot solve the problem then you can borrow some other PSU and then try with that. If that is working fine then it will make you sure that the PSU you are using is faulty. Now you also know that what you have to do. Just get a new power supply and install that to your computer. This will solve the problem for you.

A BIOS update can also do the work for you. If you are thinking to buy a new power supply for your computer then I would like to recommend you to do the update to the BIOS before buying that and see is that can solve the issue for you or not. If updating the BIOS also comes up with the same problem then there is no option other than buying a new PSU for you. I hope someone will come up with some better solution for this after this post. Good Luck!!!