[Alan Anderson]

Easy answer: your joystick's button is grounding the +5 (Aux) pin on the joystick port. +5 (Aux) is pin 1; the trigger button is pin 2. I suspect there's a short in the OI.

To work around a broken power connector, you can tether the OI to the RC and get power that way. You can also call IFI, explain your problem, and ask if they'll tell you which pin on the competition port is the power supply so you can run it untethered.

(A 2004 OI will not work with the 2006 field electronics, so you can't use it in competition.)