Is My Mobo Dead?

Question

My desktop is on the fritz and I think my motherboard's (MSI 890FXA-GD70) to blame, but just to be sure I wanted to ask. It started with my CPU (AMD Phenom II 975 BE) clock spazzing out. It went from 3600 MHz to 760 MHz (used to be 4.12 GHz), and HWMonitor said that the voltage was varying from 1.08V to 1.42V on the CPU voltage. My CPU seemed fine, but I assumed it was my PSU (Corsair CX600) dying. I took all the cables out and using a multimeter, I checked all 3 rails, which were all perfectly stable. I assumed it was a faulty CPU power extender, so I removed it. Now, when I boot it up, it works for a sec, but then the graphics (Gigabyte 760 OC Windforce) freak out and fail similarly to when my VRAM OC went too high. I first assumed it was the OC trying to kick in again, but now even when I go into BIOS, there's black lines all over the place and, even though the motherboard says the voltage is stable, the CPU clock is back down 760 MHz, implying that the motherboard is supplying the wrong voltage. The only other thing that could be a problem is if the overclock that I had tried has been written to the GPU BIOS and it's still trying it (although that still doesn't explain the CPU clock). How could I verify if it's my motherboard without potentially frying my GPU? This sucks...

Answer 1

Pull the CMOS battery on the BIOS(to reset the settings) and perform a reset on your GPU BIOS. If that doesn't fix the issue then I reccomend fully removing the GPU and seeing the performance(clock speed, etc) without any outside interference, although I don't think the GPU could be the issue. Sadly, the actual board or BIOS may be the issue, so try reflashing the BIOS, but you may just need to replace the whole MOBO.