SteppIR vertical problems

I've been using the SteppIR big vertical for about three years with 20 radials under it. It works great, but over the last winter an intermittent problem has shown up.

It seems I'm somehow losing connection with the antenna. All of a sudden, the antenna goes deaf and won't tune. I can recalibrate it a few times, and sometimes it comes back. This happened again this week, and for the life of me I can't get it to come back.

Last fall i opened the antenna up and did continuity checks, and suddenly it started working again. I guess that's what I'll do tomorrow. I may take some pictures and post here on my progress.

So far, I've removed the coax from the antenna and attached it to a dummy load at the antenna base. I get a nice flat SWR reading when I do that, so it's not the coax. I also hook my Yaesu FT-817 directly to the antenna with about a 3 foot run of coax, and get nothing buy high SWR and no signal. So I know the problem is with the antenna. I suspect either to coax connector on the the antenna, or the connection to the element within the antenna.

If you're totally confused at this point, let me offer a little more explanation. The SteppIR works by a metal tape moving to different lengths inside a fiberglass tube. This allows the antenna to be adjusted to a perfect quarter-wave vertical for any frequency from six to 40 meters. It's all controlled by a controller within the hamshack, which I've also tested. There is one spot where a spring-loaded piece of metal pushes against the tape to give the electrical connection. More details tomorrow.