normally if there are any problems with the truck it will show some kind of code on the display or a light will light up indicating which system is malfunctioning and that is normally accompanied by a code on the display.
A more detailed description of what the truck is or isnt doing would be alot more helpful.
-what happens when you turn on the key
-can you hear any contactors pulling in when you select a direction and mash the accelerator pedal?

just saying the hydraulics work but no drive doesnt really give us much to go on.