There is a long story, and a short story. Short story, to save you time so this does not happen to you - someone might be glad I posted this. I had a guest over, gave him the second remote, it was not acting right. I thought it was him.
The next day, I tried it. CRAZY!! Hard to find engine, start up delayed, engine not on track, out of RF range messages! Absolutely nuts, it worked great 2 days before.
Luckily, I knew what it was...the board in the remote must have worked loose. I watched the video again (thanks to the person that put that up!) and reseated the board....4 times. Neither time could I get more than 3 feet from the TIU before getting the bad messages.
So, I thought, "What else has changed?" (to be honest, I wanted to toss the whole mess into the garbage can - however the other remote seemed to work well.) Then I remembered that 2 days before, I wanted to up the voltage on the log loader UCS track. Bent down to move a transformer knob, and decided to raise the transformer up one level so I did not have to bend over. Moved on from there that day with my primary remote. BELOW is a picture of where that transformer sat, when the TIU signal was screwy!
After remembering the move, I put the old Lionel transformer back where it originally was...a distance of 8 vertical inches! It is shown in the second picture, on the right on the bottom shelf!
THE REMOTE WAS NORMAL!! 20 FEET AWAY, FULL, INSTANTANEOUS CONTROL!
Moved it back, all screwed up again! Someone may have experienced this before and posted, thus everyone on here is aware of what can happen, and this post is a waste of time. But, if anyone has this experience with older transformers, be aware that all the advice about loose boards, add foam to remote, reload your engine, delete and add engine, etc. - they will be a complete waste of time if it is as simple as "transformer interferrence!" Maybe this helps one person.
When I originally searched for "no RF signal" what I found was into about re-seating the board, nothing to this effect. Greg (oh..my remotes are #1 version 4.1 and #2 version 3.1 Both work fine.)