B7100 HST not working

[double hunter]

A fellow I work with has a B7100 hydro-stat that the transmission has quit, all the other hydraulics work, I would think that would rulw out the pump, any suggestions as to what to check.

 

[srs]

Fluid level ok? When were the HST filters last changed? When was the HST fluid last changed? I would start with these.

 

[Tig]

Filter screens, pedal linkage, input shaft clamp.