4 power pins on b550m

Jan 14, 2022
Can the b550m work with only four cpu power pins? I built my new pc using an old PSU (500w) since i'm not using a gpu ( the cpu is a 5700G) but the monitor stays black. I already updated the bios trough flash boot and followed all the troubleshooting but it still wont boot (i have the DRAM led on and the bios code is three long beeps). My only left guess is that i still need 8 power pins for the board to work properly, but i don't have a PSU to test it. Does anyone know if this is it?


Oct 12, 2016
Most likely this is it, but it could also be the RAM. You would have to list all your hardware in detail.

As for the PSU, if it only has one 4-pin ATX12V, it will be quite old, and the technical design will be completely outdated for today's boards/CPUs (group-regulated design instead of individually regulated rails), the 12V rail won't be the strongest, the efficiency will be bad, and the electrolytic capacitors will have aged and gone worse.

Maybe you can borrow a different PSU for testing, but actually i would just go out and buy a new one. I wrote here how to find a good one: