My display is absolutely dead

I've got a question for you if you'll entertain it. My display is absolutely dead. I've got the display out, and it's not the EMI board - it has 120VAC coming out of it. I don't know what to try next.

I do have an identical Thunderbolt display and may try exchanging known working parts - like maybe the power supply first? I'm not an expert at this but have an EE degree and adventurous spirit. If the display is the problem, would there be any other signs of life on the display?

Thanks in advance for any help. Jay C/Atlanta