With the advent of inline water filters, customers will complain about hollow ice cubes when actually all they need is a fresh filter. Restricted water flow causes hollow cubes. They are actuallly quite attractive. If a new filter does not cure the problem then a new valve and flushing out the water line will solve the problem. Follow the guidelines on "Icemaker Water Valves". Good water flow is necessary to fill the icemaker in the 8-10 seconds allowed.
It is very unlikely that the icemaker itself is at fault.
