I got a unique Machine

have a faresin Houlotte Fh 3500/14 F is the model I bought last year. Having some boom issues. Not sure why it won't move. I even have my mechanic helping me. Hoping it's something simple and not the pump. The biggest issue I'm having is no knowledge of this particular machine. Any ideas? The valves all work. I have been learning about hydraulics trying to come up with a solution. I have not looked at the suction filter yet but that's my plan.

I got a unique Machine