National 157 random reboots

This guide covers National 157 random reboots. Power stability and controller checks.

• Test line voltage and power supply output.
• Inspect door switch and service mode wiring.
• Check for loose harness connections.
• Replace power supply if voltage is unstable.

• 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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