If the 3MP31702 is tripping frequently but isn't broken, it’s doing its job to prevent a fire. You need to fix what’s causing the motor to overheat :
Worn brushes cause sparking and heat, which will trigger the thermal cut-out. 4. Replacement Guide
Use a multimeter to check for continuity across the two terminals of the 3MP unit while the machine is unplugged. Beep/Low Ohms: The protector is closed (normal state). No Beep/Infinite Ohms: The protector is "tripped" or blown. 2. The "Temporary" vs. Permanent Fix
Your motor starts for a few seconds, then dies, or won't start at all even after cooling down.
Replace the unit. These are precision-calibrated safety devices; attempting to pry open the metal housing to "fix" the internal contacts is a fire hazard. 3. Address the Root Cause
The 3MP series is often "self-resetting," meaning it should close again once it cools down. If it stays open (infinite resistance) even when cold, the internal bimetallic disc is likely damaged or "fixed" in the open position.
Slide the new 3MP31702 into the same position. It must be "fixed" tightly against the motor to accurately sense temperature.
Ensure the appliance is disconnected from all power sources.
Remove the outer housing (standard Phillips or Torx screws).