How do I trouble shoot no power at all?
Have no power at all. Is there a way to check the power system without starting to replace parts. Battery charges only to about 65% and operates another A1133 just find. The battery does get charged when installed on the dead A1133 with a green light on the power adapter. Since power gets to the battery to charge, does it mean that the main board is bad? Could it be the power button and power board?
Have you ever witnessed this machine powering on?
The problem is often that the cable that connects the power button to the board is disconnected, or needs to be re-seated, or that the entire power button/cable mechanism is defective and need to be replaced.
I'd take the topcase off (see the guides for instructions) and see if the power cable is plugged in. If it is, disconnect it, and try powering on (with the topcase loose -- there's no need to put it all the way back together for testing). If it powers on, you're all set. If not, disconnect the cable again, and use a pair of metal tweezers or a screwdriver to bridge the two pins in the socket that the power cable plugs into. This is effectively the same as pressing the power button. If it powers on, you need to replace the power button/sound electronics and cables in the topcase. It's all connected to the underside of the topcase by about 5 screws. You can also get a replacement topcase with the parts included, but make sure you get the specific one for the 1.33GHZ model 12" G4, because it's different than the previous topcases.
If it doesn't power on, it could be the board. I'd also remove the battery and RAM, just to see if that makes a difference. Sometimes the socket for the power cable breaks off of the board or is loose, in which case you're probably out of luck unless you're good at soldering.
You should not be getting a green light when charging. Try draining the battery some on the other machine and then put it back in the bad machine and see if you get the orange charging light. Meanwhile check to see if the DC port is clean and able to fully make contact with the AC adapter. Remove the battery and AC adapter, press and hold the power on button for 10 seconds to reset the SMC