Data wheel not funtioning! any one know how to fix it?

These data wheels are actually encoders. Many are mechanical and some optical encoders.

OFTEN the encoders are damaged when something hits the wheel. I have found some that have pushed the shaft causing the back of the encoder to un-bend some metal tabs that hold it together so the back comes away from the rest of the unit.

SOMETIMES I have been able to remove the encoder and re-bend the tabs and restore operation. One needs some electronic skill to do this.