Hot stamping coder not working: 1. Check if the coder switch is turned on; 2. Inspect if the fuse is blown and the power supply is stable; 3. Verify that all connections are normal; 4. Check if the intake and air tube connections are correct. If the characters cannot be printed, then: 1. Adjust the printing temperature and pressure; 2. Check if the ribbon is installed incorrectly; 3. Inspect if the ribbon take-up spacing is too small.