In a way yes I've had major problems with the Lippert power jack. Foolish me thought the jack controls and motor were water proof, nope wrong! Over a couple seasons I had so much water seep into the jack head that it caused major corrosion of the motor. Even worse when I tried to use the "emergency" 3/4 inch nut to turn the jack it just disintegrated! So I ended up buying a new power jack so we could make a planned camping trip. I eventually rebuilt the motor in the defective jack and had a real, not pot metal 3/4 inch nut welded on the emergency shaft so if anyone wants to buy a power jack cheap give me a shout  My advice to you is either always use a weather proof sock over the power jack head or go cheap like me and just always cover it with a plastic bucket.

As for your jack go buy some electronic tuner cleaner, disconnect the battery, spray cleaner in jack switches, work the switches, and you should be good after you put it all back together again and hook up the batter.