JLG proceedures are as follows:
First:
try cycling the key on and off 5 times. On each key cycle wait 10 seconds before the next cycle. This should clear any faults.

When you replaced the joystick module did you calibrate it?
this has to be done before the unit will operate correctly.
Depending on the mfg date and serial number of the unit the calibration procedure is different, there are 2 different platform consoles is why.
early models have a diagnostic port on the platform console and you short pins 2 and 3 and turn unit on to calibrate the joystick.
Later models with the newer joystick console have to be done through the diagnostic interface with handset or ground control access.