Thanks for the tip on this, I'll remember to look for that loose electrical lead the next time my HWH panel is dead.
You shouldn't have any trouble retracting the jacks if the pressure is off on the system, because the jacks have springs on the side that pull the jacks up when the pressure's off. Worse comes to worse, I think you could create a leak by cracking a fitting on a hose on one of the jacks, catching the fluid and letting some of the pressure off. I haven't tried it, but this might be an idea to get the jacks up. Some other readers might have better ideas on the jacks, since the solenoid valves I think control the slide only (maybe they control jacks too?)
Former Owner, 2006 36MDDS
2010 Arctic Fox 22GK Travel Trailer
2007 Toyota Tundra