There were responses to this thread and included pictures. Now the thread is gone?
Anyway I did take one of my spares apart and there is indeed a CR2430 coin cell battery soldered onto the internal side of the main circuit board.
It is a special made battery for this purpose and definitely not user replaceable.
Unless you know your way around electronics, PC boards, flat ribbon conductors and handy with a soldering iron as well as sourcing parts or substituting replacements then you need to take this to an electronics repair shop.
I won't repost pics here in case that was the problem but will be happy to PM them if you would like.
Thanks very much. I have three of these units so it may be something to try. If it is not too much trouble, I would like to take
a crack at this and the pictures would definitely help. [email protected] or 970,274.1718