first check the simple thing. they either have an on/off switch and manual bin full bail.

the bail is a wire or metal arm that detects when the bin if full of ice. On some models to turn off the ice maker you lift the bail up until it clicks.

It is possible that it or the switch was accidently hit.

but there are many different types and models of icemakers. If this does not help you need to give the make and model number.