We've had a few calls telling us the air pressure sensor light is on, on the front panel.
On the 2009 models, the light came on to warn you air pressure was too low and it would not allow you to use the cutter. The manual reflects this.
On the 2010 units, the light is on to let you know the air pressure is in range.
A simple test. If you turn the air pressure under 25-30PSI and LED/light status changes, the sensor is working and you are fine cutting with the unit.
Either way, if you're not in range the cutter will not allow you to cut and protect the unit.