Gigabyte GA-H77-DS3H wont start

I am using Gigabyte GA-H77-DS3H motherboard with Core i3 processor, Kingston DDR3 RAM, GTX 660 graphics card and Corsair 500Watt power supply. I have been using this system for quite long time without any issues. But yesterday it shutdown autmatically and it is not booting at all. I have disconnected every hardware and reseated the graphics card, CPU as well but for sometime the pc will boot then again it will shut down automatically and wont boot. Can anyone tell me how do I solve this problem? Thanks

After reading the problem that you are describing it seems that there is a problem with the Corsair power supply that you are using. Can you tell us whether your computer buid was surge protected? It looks like some parts of the computer just got fried which is why you are facing that sudden shutdowns. Are you getting any burnt smell when you are removing all the hardware outside of the computer case?

Even I agree that there seems to be some problem with the Power Supply that you are using? How old is the PSU? If it is under warranty period then perhaps you can send it to RMA and get a replacement psu. Other than that, you can also try to run tests of your hard drive, graphics card and the processor as well. The Corsair 500W seems to be a cheaper model power supply and you need to make sure that it isnt damage or something.

First of all I would suggest you update the motherboard BIOS to the latest version. After that check in the BIOS menu and ensure that all the peripherals are seen as present and properly. Next, you could try to use decent Sata cables and connectors and then disconnect and reconnect all the cables for power and Sata. You need to also check the voltages in the BIOS if 5V is approximately 5V and if it is not then better try another power supply as well.