Power Jack issues

Friday afternoon hooking up to go out for the weekend, elctric tongue jack worked fine to raise. Positioned the truck, and parially lowered onto the ball. Next connected the spring bars and when I went to finish lowering the tongue the jack was dead as a hammer. Nothing up or down, no sound, no clicking, nothing. Checked the fuse, checked the connection on the battery, even tried putting a jumper directly from the battery negative to each of the mounting bolts, still no response. I broke out the ratchet and loosened all 3 mounting bolts. The jack shifted about 1/8 of an inch. Looked like it was under some strain/bind from the angle of the trailer against the chocks. Tightened up the bolts and every thing worked. I think it was the angle binding the jack, but maybe the bolts loosening and tightening re-established a ground? All works well now.