Apple Cinema Display Repair : Luke Cyca Dot Calm

Here's another nice piece of kit that I scavenged from a pile of e-waste. The 23-inch Aluminum Apple Cinema Display cost $2000 USD in 2004 (discontinued 2008). It still looks great today, and with a resolution of 1920x1200 it's still plenty usable. I actually already had one (which I bought for $50 from FreeGeek a couple years ago) so now I have a matched set! Perfect to go with my 2008 Mac Pro!

This one didn't turn on. Apparently a common problem in this model is the "short long short" LED sequence, indicating a power supply issue. On the Internet there are lots of people suggesting a workaround in which you block the middle (sense) pin from the power supply brick, either with scotch tape, or by modifying the power brick itself. This effectively just bypasses a protection circuit though, patching over the symptom and leaving the root electrical issue to fester unchecked.

Over at this forum post and this other one they hint at the root cause: a failed 3.3v voltage regulator. Mine had the same symptoms: it was outputting ~4v instead of 3.3v.

I didn't have an LM1117-3.3 on hand, but I did have a bunch of AZ1117CH-3.3, which is pin-compatible if you squint a little. It has slightly lower spec for thermal performance, but it has a higher current rating, so I figure it should be sufficient. If it fails again, I would probably replace it with a LM1086CS-3.3 which is actually pin-compatible, and with a higher current rating.