It's not the best idea to go doing that, as it's designed to be powered from multiple sources and the MCU controls and 'knows' which is being used. Hard wiring it for only one could cause issues.
Does it show any signs of life from any of the 3 different power sources? AA pack? PnC pack? PnC cable?
If all you have are the AA packs, then very first thing you need to check is the plastic tab in the battery compartment of the controller. It's pretty much dead center in there and sticks up 1/8" or so. It makes the switch (2 metal tabs) inside of the middle of the AA pack close. That plastic tab in the controller can break, or the metal tabs in the AA pack can get bent and not make connection when it's installed and you'll have a dead controller, again only applies to AA packs.
If all you have is a single PnC pack, the data in the EEPROM in those things can get corrupt and the pack becomes useless without reflashing it, and even then it's a 50/50 shot if it will hold or just happen again.
