8 pin and 4 pin CPU Power connectors on MSI MPG2390, blew out my PSU (CX750)

I have a continuation question on this thread:

Do I need both the 8 pin and 4 pin cpu power plug for my MSI B450 Pro Carbon?

I had issues with 9900K on an MSI MPG Z390 motherboard and an NVIDIA 2080GTX card rebooting my PC every time I pushed the graphics content hard.

So I realized I had only plugged in the 8 pin CPU power and saw that my Corsair CX750 didn't have any 4-pin power plug cables so I plugged in the 6-pin power and it fit on the 4-pin CPU power plug.

When I turned my PC on it blew out the power supply in the least and I pray I didn't blow the motherboard and everything on it. A "poof" sound and a tiny bit of smoke and burnt smell!

When I check the manual it says that all the CPU Power Plugs all take 12V. These plugs are all seemingly 12V. Could it be that my PSU was just tired and decided to retire?

Any first-hand-knowledge would be highly appreciated on this.

1 Answer

Check this diagram:

Although 6 pin fits 4 pin connector, the power (+12V) and ground lines are opposite. Basically you have short circuited your PSU. You can try replacing PSU and see if your hardware still working, but there is no sure answer.