Should I replace the inverter or the motherboard first?

Hello,

I have a 35in zero-g curved ultrawide gaming monitor v2. My warranty is expired and I'm seeing if i can fix it. When i plug it in the LEDs on the back flash for a moment and then nothing happens. It stopped working after i was rearranging my set up and plugging in stuff. Anyways i was testing the inverter inside to see if it was delivering power. And it is, but it's doing over 12v. 18 and and sometimes 20v but the board says it should be putting out 12v

Is this normal? Or is it potentially part of the problem. I'm just trying too figure out which board i should attempt to replace first

Board models are:

Inverter: AY076D-1SF02

Motherboard: jry-w9cuhd-av1