Not sure why, but tracking down a datasheet or service manual for the LG-Phillips LM201S01(ST)(B2) LCD monitor has been much more challenging than I would have thought (the datasheet appears to be available for download from this site, but there's a complex paywall that I lost patience with). After a week of searching, I pulled the following image off a Russian forum, and it claims to be the official pinout for the 30-pin monitor connector for our monitor:

This pinout matches most of the other data I have, except for one major inconsistency: this pinout indicates that VCC for the monitor is 12V power, while the labeling on the actual connector (the small connector opposite the 30-pin LCD connector) clearly says 3.3V.

So is VCC for the monitor 3.3V or 12V?