In article , David Walters
writes
These are the LEDs that helpfully turn red at the moment when you put a
valid paper ticket in?

Yes. Swipe too quickly and the red one comes on.

But why have the LEDs come on *at all* when you use the paper ticket?
--
"It used to be that what a writer did was type a bit and then stare out of the
window a bit, type a bit, stare out of the window a bit. Networked computers
make these two activities converge, because now the thing you type on and the
window you stare out of are the same thing" - Douglas Adams 28/1/99.