Either CPU or Mobo dead. Which one is it?

BSulyok

Commendable
Apr 29, 2016
8
0
1,510
A few days ago my PC suddenly gave in and didn't turn on ever since although the past 1.5 years it worked without any similar failure. When pressing the power button the front panel power switch LED lights up but nothing else happens: no beeps from Mobo speaker (with or without RAM), no PSU fan, no CPU fan, no GPU fan, HDD is silent as well. Shortly after I disassembled the whole thing and got somewhat closer to the problem. RAM out, HDD out, GPU out and I'm left only with PSU Mobo and CPU. Now I know for sure my PSU works well because:
1: I tested it in another machine which managed to boot up with it.
2: I linked pins #15 and #16 of the ATX 24-pin power supply connector which are supposed to simulate a power-on state and the PSU fan started up. Then I hooked it on a Digital Multimeter and all voltages were within the treshold of +/-5% of the values indicated on this website.

All capacitors on the Mobo looks intact at first sight (none seems to be burnt or deformed) and I don't really know how could I test those reliably. For some reason this Mobo came with no power LED on it.

My CPU: AMD FX-8320 3.50@4.00GHz 16MB AM3+
My Mobo: Asrock 980DE3/U3S3
I would be more happy to find out it's the Mobo since that was a lot cheaper.

So my question is am I looking at a dead Motherboard or a dead CPU?