My PC won't POST ?
My PC won't POST ?
So you've had 2 board changes within a 1 year time span. Either you have really bad luck or something else is going on inside of your system. I want to clarify if your PSU is the Gigabytes GP-P750GM?
Because if it is, they have history of catastrophic failures as one example of
poor quality control
Also, do you have a surge protector between your system & the wall socket where electricity comes from? If you get a mains power surge or brownout, then the PSU will be the first port of call to cop it. Safety mechanisms on that device will kick in to protect the system for one potential power surge, but if you get another power surge or brownout, there is no guarantee the PSU safety mechanisms will still cope ok. There maybe enough power supply from the PSU to boot with the lights on & fans spinning but not enough to do a full system boot in some situations.
As is the common rule when diagnosing hardware problems, use a known working unit to test if your PSU is faulty or not. Everything has to be done step by step first, then move on after the results of that.