This is the screen in question
I think maybe trying to source an ad board might
Be best option from usa
I can see this machine being a money pit😂
If you can find an A/D controller that may be your best bet, assuming the rest of the monitor is functional.
I was really surprised when you swapped out the power supply and it still doesn't work. The old power supply may have damaged the A/D board when it died? Who knows.
If you want a real money pit, buy a RV