There are several ways to check if a peanut shelling machine has failed after long-term use. Here are some steps you can follow:

1. Observe the machine: Check the peanut shelling machine visually and look for any signs of wear and tear. Examine the structure, belts, pulleys, and bearings to see if there is any visible damage or misalignment.

2. Listen for unusual noises: Turn on the machine and listen for any unusual noises such as grinding or knocking. These sounds could indicate a problem with the gears or bearings.

3. Check the power source: Make sure that the peanut shelling machine is receiving the correct power source, and that the voltage and frequency are correct.

4. Test the performance: Run a test with a small batch of peanuts and check if the machine is performing as expected. Look for any problems with the speed, efficiency, or output.

5. Check the maintenance records: Review the maintenance records for the peanut shelling machine to see if it has been regularly serviced and maintained. If not, this could be a cause of failure.

By following these steps, you can identify any issues with the peanut shelling machine and take the necessary steps to repair or replace it.