One PWR source must supply GAPCU (Battery, IDG, or APU GEN)
- Disconnect GPU from A/C
- Cockpit Elec PNL -> Battery must be "ON"
- Reset External PWR PB -> "ON" then "OFF"
- Reconnect other GPU
- Failure of the Ground PWR Unit to supply A/C
TSM-24-41-00-810-833-A
