Pc not booting into bios

[rohith1371]

Hello guys,
My name is rohith.
I own a pc. One day suddenly my pc stopped booting. I changed to new motherboard and memory. I tried everything. But nothing seems to work.
Motherboard : gigabyte GA-78LMT-USB3.
Ram - g skill 1600mhz ripzaws
Processer : phenom 2 x4
Processor fan running
Power supply also seems good
I don't understand why it doesn't boot

 

[PC-4LIFE]

Could be a dead GPU or CPU.