I have a G3 PB that is hard to start. I have replaced the PRAM battery twice. I also have the L-ION battery, which is fully charged, and I also have the power adapter plugged in and working. The only way I can start the PB is to remove Power adapter and the L-ION battery for five minutes. Then I will hold in the reset button in the rear of the BP for 45 sec. Then I would replace the battery and power adapter and hold down the on button for 3 seconds before I hear the PB chime ring. I have sent the BP to a repair shop before, they told me the power controller card needs to be replaced. My question is what do I need to replace? The Sound / AC input board or Power / Charger board?

If you have your PB plugged in and it has the problem, it most likely is not involved with the charger board. The charger board really only sends power to and from the batteries.

Try taking out your li-ion batteries and just use the AC, and see if you have a problem. If you do, you can pretty much rule out the charger board.