No Cubes

Make sure the water going to the refrigerator is on. If the refrigerator is equipped with a filter, it could restrict the water flow to the ice maker. The other possibility is that the ice maker or water solenoid is bad.

Small Cubes

This is possibly a water restriction caused by a filter or a bad water solenoid.

Leaking

If the water is leaking on the floor, it could be a bad waterline, water solenoid, or frozen water dispenser. If the water is leaking in the freezer, it is probably a bad ice maker. If the coating on the ice maker wears out, the water can leak easily and you will probably see icicles.

Slow Production

If the freezer is not cold enough, ice production will slow. If the freezer is above 10 degrees, ice will not freeze quickly at all. 0 to 5 degrees is the best temperature for ice prodution. Cleaning the coils will enable the freezer to cool more efficiently. The ice maker has a heater. If the heater is not working, the ice maker slows down dramatically and will eventually wear out.

Disclaimer: For safety, check and obey all national and local electrical laws and permits.