Diagnosis
The tool is overheating. The thermal protection circuit is tripping. This is usually due to overload or insufficient battery power.
How to Fix It
You are likely pushing too hard. Let the tool do the work. Use only moderate pressure. Ensure you are using a high-capacity battery (5.0Ah or higher) for extended sanding. A small, old battery cannot supply enough current and overheats internally, causing the tool to fault.
If That Didn't Work
The motor or electronics may be failing, causing excessive current draw. If it happens with a fresh, high-capacity battery and light pressure, the tool needs service.
Heads Up
Sanding pressure should be 10-15 lbs max. More than that stalls the pad, overheats the motor, and gives worse results.