National 157 snack motor failure

This guide covers national 157 snack motor failure on legacy vending models. Diagnose motor and drive faults.

• Check motor output at the controller.
• Inspect couplers for wear or slippage.
• Verify selection switch status.
• Replace motor if it does not cycle.

• Perform a controlled test after each adjustment.
• Document the changes and results for future reference.
• If the issue persists, swap with a known-good component.

• Clean components during each service visit.
• Log repeat faults to identify wear patterns.
• Keep spare parts for legacy models on the truck.

• You have repeated failures after controlled testing.
• Safety or electrical issues are suspected.
• You need model-specific parts or OEM guidance.

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