Hi, I appreciate the teardown here.
I recently had a problem with my Thunderbolt Display turning black after short period of usage. Ranged from minutes to hours. The display was still recognized by the computer, it's just that the screen was black. After turning it in for repair a technician said it was the logic board, and changed it and charged me. It worked for a couple of days and then the same problem was back. This time the repair shop says it's the LCD display. My hunch is that it was the LCD all the time. My question, even though a bit vague: would my computer be able to recognize a display with faulty logic board? It feels like I'm being tricked by the repair shop.