Malfunction perhaps?
I know my old SOS beacon after time would not make contact when the plunger was installed... If you pulled on the cord it would shut off.
I had to tape it to get it to work.
I bought a new ortovox since then.
FYI for anyone with the old SOS black and yellow beacons... Seen more than one do the same thing.
We have 4 of those old black SOS beacons. 2 of them have the yellow plastic broken that sits down inside that presses on the little rubber plunger inside the unit. Non-operational now. We have two that still work. Hope that plastic doesn't break on them too.
Might need to pony up for new beacons.