I think you may be mistaken - in my IA-1, there are actually three connectors that go to the 'Front LCD Pannel', one of them is for the microphone, and the other two go to the motherboard. The big 30 pin one on the left is the actual LCD signals, (including backlight maybe?) and the other 12 pin one (CN6 on the silk screen) is for the buttons and the LEDs on the front.
The more important question, though, is how to turn those darn things on! I'd love to know too. It's just probably just a write to the I/O pins on the VIA chip, but I have no idea how to do that under Linux!