Thunderbolt Display Issue & Resolution
This isn't a question, more so a solution to a problem I just resolved. I bought a TB Display off Facebook, and the monitor worked fine that night. The next evening, the screen wouldn't turn on. I have it connected to my new M4 Mac mini via TB2 to TB3/4 adapter. I began to troubleshoot.
I connected it to my outgoing 2020 27" iMac with the same adapter to see if my Mac mini was the issue, screen wouldn't turn on. I then plugged it into my 2012 MacBook Pro, without the adapter since it still used the old TB2 cord. Screen wouldn't turn on. I found that my screen wouldn't turn on, BUT it would charge my MacBook Pro with the built in MagSafe cord, which really through me off.
After several hours of searching this forum and others, I couldn't really get an answer. I decided to buy a thunderbolt 2 to thunderbolt 2 cable, and I plugged one end into the external TB port on the TB Display and the other end into the TB2 to TB3 adapter (connected to the Mac mini). Screen turned on!
So, in summary, if your Thunderbolt Display charges with MagSafe, but won't turn on the display and you're using the built in TB cord, try using an external TB cord. I paid $10 (11/2024) for an open-boxed cord from Best Buy and had it shipped to me (only took two days, really shocked). Hope this helps someone in the future!