I have an old Timex Ironman Triathlon. I was just pushing the mode button to see if I had left the stopwatch running, when it beeped and the display died. 

I guess I'll have to unscrew the back tomorrow.
Edit: I tried pushing all three side buttons at once. It beeped and then started up!
Everything is reset like I had replaced the battery, but that won't be hard to program.
I guess I'll have to unscrew the back tomorrow.
Edit: I tried pushing all three side buttons at once. It beeped and then started up!
