Okay, so here's the long story.
I recently purchased a Mid-2005 G4 ibook, without an LCD. I currently use a G3 dual-USB ibook, and happen to have a spare LCD (with frame, etc) laying around. I bought the G4 with the explicit intention of mounting the spare LCD on the headless G4 body, not unlike This project.
So, here's what I did -
1. Bought the correct LVDS cable and inverter cable (with no reed switch).
2. Opened up the old LCD, cabled it up with the new cables, and closed everything up.
3. Mounted it all on the G4.
And.... it didn't work. The backlight won't turn on.
So here's my troubleshooting process -
1. Switch out inverter board with known good (from a G3 - they're the same part number, so it shouldn't matter? No change.
2. Switch out LCD panel with known good (from both g3 and earlier model G4). No change.
3. Confirm that by leaving the back open, and sitting the damn thing in front of a light, I can see everything on the screen, and use the laptop. So, the LVDS cable is working.
4. Use a multimeter to check the inverter cable for continuity. Tests perfect.
I can't imagine why this isn't working. My guess is that I'm down to a logic-board problem? I read (pretty poorly) the voltages coming off of the logic board with an o-scope, and there's voltages on all 4 pins. Whether or not they're right, I don't know.
Suggestions? I've currently got it at a mac-repair place, only because they've (theoretically) got more resources than I do, more parts to swap out to try and find the source of the problem. They apparently haven't even touched it yet (after 5 days...) and I'm thinking about just getting it back from them.