yes I have had lots of range finders of many brands and costs from cheaper to some very costly one's fail
there electrical item,s and well, as such, things fail
add in we hunters take them in from COLD temps to warm temps, , condensation forms on contacts and as time passes they corrode and fail
I have this same issue with trail camera as well, they will work fine for yrs then just STOP< no warning
I have also had this happen with high end camera's as well
sadly, its kind of the nature of the beast IMO
electrical parts can fail at any time it seems, from parts on vehicles to what ever!
sucks, but, Is what it is
and I idea you can try if you wish
on your old range finder you can try taking apart and cleaning contacts with electrical contact cleaner, never know, won;t hurt at this option
and in the future, you can also try storing things like this in a baggie filled with dry rice, it helps suck moisture off things and into rice?