Manitou 630-125 lost drive

[robin banks]

I have been asked to put up this question. The farmer has manitou 630-125 its a 2012 loader apparently very like a redrock. He was driving on the road when it lost all drive to the wheels. He can use all hydraulic functions but won't go forward or back. It goes through the gears fine and put it in reverse and the beeper goes. He says he doesn't think its a mechanical fault as no grinding or unusual noises.
Any ideas what it may be

 

[JLLM]

Switch in the seat?

 

[del_boy]

Switch in the seat?

Handbrake switch another thing to check