Tovis L43E5LT1BY Colors and Backlights

[BigWick]

I've seen two of these do the same thing.
Monitor comes in and powers up on the bench with backlights but will only cycle through red/green/blue/white/black and never prompt "Check signal cable" like a known good monitor will. The status LED changes red to green when I give it a video signal so it detects something.
Swapped the TCON - no change.
Ordered a replacement A/D board (Tovis UD120 Rev1.01) and it's visually identical down to the manufacture date (but the VGA port has been deleted) but when installed as soon as the backlights turn on my bench supply kicks out. Unplugging the LED driver harness from the board stops that but I can still see it cycling colors when I put a flashlight up to the screen. The pinout for the LED harness on the old and new boards are identical.

I put the original board back in and the backlights work again but I still have the cycling colors and I cannot see anything on the new board that would cause the backlights to kill power as soon as the backlights are turned on.

There was a discussion about this on Delphi Forums back in 2019 but it didn't lead anywhere. - https://forums.delphiforums.com/slottech/messages?msg=18110.1

[BigWick]

I reseated the LCD to TCON, TCON to A/D and the other cables on the A/D board and it came back with the original parts still in it. Not sure what I did, but it displayed a picture and continued to do so when left overnight and then power cycled/the machine rebooted. I bet you $20 I send this back out it'll fail again because I don't know what it wanted.

It does still have a bad DisplayPort. Is there a better part number for this board beyond "UD120_REV1.01"?

[Firebird]

UD130 was the original A/D board for the one we had. Found one at Patriot Gaming.

[BigWick]

This one? https://patriotgaming.com/a-d-ud130-v1-4-i-o-port-dvi-dp-twinstar-j43.html

That one didn't work either. Same issue with it shutting everything down as soon as the backlights fired.