Flydrone. You are correct, BUY a new loader (charger). There are screws under the bottom foot pads to disassemble charger. But then what?
The non-functioning charging door (station), let's name it 3, is the station at the opposite end from the USB power connection. With no batteries charging, the 3 station LED is extinguished and 1 an 2 stations LEDs are slow flashing green sequentially. If only the 3 station has a battery installed its LED remains extinguished. If a battery is installed in either stations 1 or 2 or both 1 and 2 then 3 station LED is solid red. 1 and 2 stations function normally; that is the highest voltage battery station flashes green and the standby station is solid amber. There are numerous other combinations of battery installation with different LED outcomes, but who cares. BUY a new charger.