CPU shutting down after some time

[sm159]

Hi Everyone! I have recently bought a GIGABYTE GA-78lmt usb3 Rev5 for my AMD FX 8320 processor. What I have noticed is that, it shuts down itself after a period of 30-45 minutes without any warning! Also I've checked the temperature of the core, mobo and graphics card which is around 30-40 degree Celsius and thus no cause of overheating.

My specs are as follows:
AMD FX 8320 8 core cpu
GIGABYTE GA-78lmt usb3 Rev5 motherboard
2x4 GB DDR3 RAM @ 1600 MHz from Kingston
500 GB SATA2 HDD
ATI Radeon HD 6570 1GB graphics card
500W PSU fro FOXIN

[autotech]

I wouldn't trust a 20.00 power supply with that build, especially the brand you mentioned. You can find so little info on what the 12 volts rail carries as far as amps and so on.