I had received (among other assorted junk) a pair of 23″ Apple Cinema Displays (resolution 1920 × 1200) from my previous workplace for free some years prior. I had used these as second monitors, one at my parents' and one at home. The monitors are excellent, especially given their age, but they have a common problem where an insignificantly heatsinked voltage regulator would fail over time. Here's a good video explaining the issue (YouTube). So, when one of the displays refused to start one morning and giving me the dreaded short–long–short error code, I knew what I was up against.
Indeed, when I extracted the display unit out of the case and measured the voltage regulator, it had drifted to 4.11 V (it is supposed to regulate 5 V down to 3.3 V):
The other monitor had actually developed the same issue a couple of years earlier, and when I had been fixing that, I had ordered two replacement voltage regulators in case I messed up one of them when soldering. Alas, I didn't, so I already had the spare part at hand.
After replacing the regulator, the measured voltage was back where it was supposed to be:
After reassembly, the monitor came back to life just fine:
This post was retroactively compiled on 2024-01-05 from photos in my photo library.