How long is a bread machine suppose to knead the dough?

I'm on second machine and it's been kneading for 15 mins!

I figured the first machine was defective cuz 2 buttons didn't work and the
timer didn't progress. I threw dough in 2nd machine and it kneaded for 3
mins, then rested (doing whatever) then started kneading again. Been
kneading for..... well. At least the timer is advancing. Is this normal?
Do the damn things ever BAKE!!??

nb