Could I need a new power adapter or is something else awry?

I have a 23" Cinema Display that does the same thing. It powers off on its own, and then won't turn on unless it's been unplugged for a while. I used to only have to leave it unplugged for 15 minutes or so, but lately I've had to unplug it for at least an hour before it will turn on. I've been meaning to try swapping out the power adapter, but I need to find somebody who can lend me one.

It's definitely the power supply. After shutting itself off, mine started needing two hours to "rest" unplugged before it would power up again, so I opened it up to try to better understand the problem. There's no good way to open it. I used a Dremel to carefully cut around the seam until it was thin enough to crack apart.

There's one huge capacitor (Rubycon KXW 450V 150 uF) that needs to be discharged before the power supply will start up. Be careful, because it's charged to over 100 volts. I soldered a 600 k ohm resistor across it to bleed off the charge a little faster.

I can reproduce the problem by unplugging the power supply while it's on. Now it only has to "rest" a couple of minutes instead of a couple of hours.