JD 410 stuck in my driveway!

I've posted on this machine twice now. My issues with it have gotten worse and I'm not getting any where with it, it now has dead hydraulics and is sitting in the middle of the driveway were I moved it to work on it. Not a big deal to me cuz I think it's a good looking machine:D but my wife is a WHOLE nother story! This is what I've done, I've checked the pickup screen, changed filters and hyd. Fluid. I've checked pressures at the hydraulic pump, my main pressure was low slightly and my charge pressure was fine until I moved any function then it drops to zero, since the problem has gotten to where the hydraulics are dead, my charge pressure stays at zero. I disconnected the feed line to the main pump ran it into a bucket and got aprox. 4 gallons in 20 seconds of running the engine. I have removed a piston in the main pump at it looked it really good condition. I've checked the transmission filter relief valve and it seemed okay but I'm not sure exactly what to look for. On top of it all the machine slips in high range, pulls ok in low range. I figured the problem could be connected. Sorry for all the info at once, I'm not sure what to check next, my guess was pressure regulating valve but can't find where it's located. I'd really appreciate any help.

JD 410 stuck in my driveway!