Hi, I bought this machine with dead battery so I've purchased reman one. Lift was stubborn at first but after few tries it did work great. After about 15 mins of use right after I stepped off the machine it displayed code 74 and 75 and once 76. I've had Flight systems go thru lift amp and controller and I did replace diodes. Still same problem after reinstalling the controller and lift amp, I did check wires from joystick to controller and everything is looking ok.......Any idea what I should check next. Thanks