Error codes: MLC76, MLC77, MLC81, MLC83, R44.11, R44.12, R45.0, R45.2
The sensor that verifies the ATC is back in place or extended for tool change is not activating the sensor signal telling the machine it is at the correct location.
At your utilities page you can make your tool cylinder go in and out (must be in JOG mode). Verify that the sensor red led is on once it returns or extends. The sensor that is not activating needs to be adjusted or is broken.
To adjust make sure cylinder is at correct position (extended or retracted). loosen the screws on the sensor hold down and slowly move the sensor up or down until the led turns red. Retightening the hold down once led is on. This error should be resolved.