I am wondering if my Thunderbolt Display is about to be dead. I started noticing that it will sometimes start flickering on and off a bunch of times. Sometimes it stops, other times I unplug it from my Mac Mini thunderbolt port, and plug it back in; and it comes back on and is fine for a while. Now I've noticed it going to "sleep", which may be sleep or may be just the display being off; and it won't come back to life when I tap the trackpad or keyboard (both Bluetooth). Usually unplugging the display and plugging back in turns it on. On a few occasions I've had to reboot the Mini to get it back on. I'm wondering if it is possibly the cable, the power supply, or just dying. Apple replaced the LCD panel several years ago. That is the only problem I ever had with it. The outer white skin of the cable has been cracked for many years, but inside the cable looks completely fine. It is so old that I don't want to dump a lot of money into it, but would be willing to try and replace the power supply myself if that is likely the problem. I can get a 3rd party display for a few hundred bucks. Hate to part with it though as its so nice looking!