2007 Doosan 440 Plus Skidsteer runs, but does nothing else! Help!

[jkeehn]

Got a buddy who has this thing, and it runs fine. Auxiliary hyd works, but main hydros and steering does nothing.
He's changed out the relays, and checked a couple things, but no dice.
Any idea where to start?
Plus, where can I download the operation and maintenance manuals?
Would really like a schematic.
There is a push pull knob on the right side behind and aft of the right side joystick.... what does that do? It's not the parking brake, because that is labelled. Any idea?

 

[foton]

just as a guess that knob might be the emergency hydro release. like the engine dies when the bucket is up and you can not get out of machine ,you would pull it and the hydro will bypass and the bucket will lower. as for the other problem have you checked the lap bar or seat belt switch?

 

[jkeehn]

Yes. It looks like that's what the button does.
I don't know if it has a seat belt even. I'm looking into the safeties. I'll get back to you.