We were camping with friends for several days leading up to the Friday of a long weekend. Friday morning we packed up and were ready to go so I started the engine and went to push the retract all button and nothing. No lights, no bells or buzzers, just a Bounder up on jacks. I checked fuses and jiggled wires but there wasn't much else I could think of to do. I called Good Sam ERS. They found a mobile RV mechanic and covered the dispatch fee.
The mechanic checked the fuses and jiggled some wires and then hot-wired the hydraulic solenoids to the battery and up went the jacks. Clearly the problem was electrical so I had a starting point. Once back home the sleuthing began. Turns out it was the connector that joins the control panel to the wiring harness. There are only 4 wires in a push on connector so I went to an electronics supply place and got replacement parts and soldered them up. Presto!
Ah, but the saga doesn't end there. The next year, the jacks started acting up again but this time there was no power coming into the control panel. I crawled around following wires and found the control module and levelling sensor screwed to the 'ceiling' of the basement compartment over the propane tank in the front-most curb side compartment. This is where I store the outdoor carpet / mat but I never noticed it there before.
I got the wiring diagram from Power Gear and spent a few hours testing everything and came to the conclusion that the power pass-through relay was fried. Bypassing it let everything work - up and down. I simply soldered a jumper into the wires before they went into the module and everything now works as it should. And I didn't have to sent Power Gear many, many hundreds of $ to do it.
That was May 20, 2019 and we have used the jacks for 100 nights out since then so it looks like a permanent fix. Diagnosing problems and finding cost effective solutions is part of RVing with an older rig like ours. I like the satisfaction of doing it myself.