Problems With Power

So I'm pretty sure I found the pinout for the native inverter, however, despite my best efforts, I wasn't able to get it working. To be fair, I couldn't be sure it ever did work. Part of the problem might have been my power supply. At first, I was hoping to use the iMac's power supply which is compact and custom made to fit inside the top of the iMac's dome. However, After a bunch of reseraching, I found there's not a whole lot of info online about the iMac G4's custom power supply. (Quick note on the pinout there, the BL on/off pin should require 5V via a 1K ohm resistor. Also, the dimming seemed to require between 3.3 and 0.8V to adjust the brightness of the display. I wasn't ever able to get that working however, and only had a 5V source to work with. I'm sure I'll be revisiting this one soon, though...) So here's what I found:

The iMac's power supply will only work if it's connected to a ground. In the iMac G4, only two lines actually go from the plug to the power supply. The ground wire deviates and screws into the metal internal shell of the computer. As far as I can tell, that's used to ground everything inside the machine, Including the power supply. Therefor, the power supply won't work unless it's installed in the computer the way it's meant to be and a ground cable is connected to the metal base.

But that's not all. Ther are four yellow and one blue lines coming out of the iMac G4 power supply (each with a corresponding ground wire). I'm not sure what the blue wire is, but the 4 yellows are 12V lines coming into the motherboard. (They actually read something like 14.8V)

Unfortunately, that's all you get from the power supply. If you want the 12V & 5V lines used for the CD & Hard drives, this cable has to be plugged into the motherboard and the computer has to be turned on. Whatever they do to drop the voltages, they do it on the iMac G4's motherboard. So as far as I have figured out so far, the G4's power supply wasn't going to work for me.

My solution was a DIY power supply. However, I'm not entirely sure my power source was up to the task. To make it, I used two AC wall adapters (5V & 12V), combining the negative wires together. This worked great for powering the video controller, but might not have been enough to power the inverter:

On the power supply for one of the monitors I have disassembled, It listed all the input and outputs for power. It looks like the inverter requires 12V @ 0.4 amps and 5.2V @ 3 amps. Unfortunately, I wasn't able to find a 5V AC adapter with more than 2.3 amps, so that may have been part of the problem....