Quoted from lyonsden:
End of stroke lever for a flipper. Important piece that cuts off the high power to a flipper coil when holding the flipper up. Find from which flipper it broke off and replace before playing again. You can burn the coil, short a transistor, etc if not fixed.
Sort of. On a pre Fliptronics era pinball, that’s correct. No EOS switch = hot coils and eventual disaster.
On a later model machine, like X-Men, the flippers are controlled by timed pulses. So the EOS switch is made redundant by the process.
What it’s used for these days - when the flipper is being held up by the 12v, if a ball hits the flipper and makes it fall down (with force) the EOS switch will close, telling the CPU to fire the 50v pulse again to hold the flipper up.
That’s why the side flipper has no EOS switch.
So, the EOS is not as important as it used to be, but you want to fix it up when you get a chance.