Restore Power Path by Replacing Faulty Controller or Battery

Safety Warning: Before performing any work, ensure the battery is disconnected from the bike to prevent electrical shock or short-circuiting the system.

1. If the multimeter reading at the controller input showed no voltage, inspect the battery discharge cable and the battery mounting plate for corrosion or loose connections.
2. If the battery terminals are clean and tight but still output no voltage, the battery management system (BMS) may have failed internally, requiring the battery pack to be professionally serviced or replaced.
3. If the battery provides full voltage to the input but the controller output to the display remains at 0V, the internal power regulation circuitry of the controller has failed and the controller unit must be replaced.
4. Once the faulty component is replaced, reconnect all wiring, ensuring the SM-5Y connectors are fully seated and free of debris.
5. Verify the fix by switching the battery to the 'ON' position and pressing and holding the center 'M' button on the display for 3–5 seconds to confirm the system powers up.

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