sorry to resurrect this thread, but did you ever get it fixed? Having an identical issue including hydraulic slides coming out while in storage. Recharged the batteries and landing gear will not retract or extend but I can hear the motor spinning, may be bad pump. I'll take a drill out there Saturday and see if I can operate the landing gear manually.
Update: My landing gear switch broke, so I changed out the switch from a six pin to 4 pin switch. Landing gear jacks still would not retract with either battery, shore power or auxiliary back up (drill). I traced the lines and there is a solenoid on one jack to isolate the cylinders from the pump, mine is on the passenger side only. I found the Lippert manual and the valve must be opened manually with a 5/32" allen. Now landing gear extend and retract normally as long as the solenoid is manually opened. So I may have a bad solenoid or electrical connection.
https://www.lci1.com/assets/content/...ers_Manual.pdf