I think most hams have made the mistake of jumping to the complex problems (my autotuner's at fault) first before checking the basics (coax connector)! I know I have.
After getting to know the MFJ folks in the repair area, I suspect that at least one or two of the "junk" comments could be due to this. Not all but a few! I know they get returns and just cannot replicate the reported symptoms.
Glad it was a "cheap" solution...
THis probably doesn't belong in this thread, but I'll say it anyway, just in case it helps somebody else--though it's not likely anybody else will be this boneheaded.
I've had that autotuner up and down several times; it would work occasionally, then stop working. Take it down, take it apart, run the reset procedures a few times, it passes its self-test fine ... but then it doesn't work when it goes back up. For a few weeks, it would work just for a few minutes or hours. Then starting yesterday, it never worked even intermittently, it was dead on all bands.
I was totally stumped and was getting ready just to buy a new autotuner, when it occurred to me to try replacing the coaxial cables and using a different bulkhead passthrough, through the wall. Now it's working fine. It *might* be coincidence, but I don't think so; I think it was either a intermittent chunk of coax or an intermittent bulkhead passthrough.
I guess I'm glad I tried it, but I sure feel stupid for not thinking of it earlier. :-/