Zappi emits a loud buzzing or humming noise during charging.

Safety first: Some low-level hum is normal, but loud or new noises should be investigated.

• 1. Identify source: With the cover on and charging active, carefully listen to locate the area of the noise (top, bottom, left, right).
• 2. Tighten mounting: With power off and the cover removed, tighten screws securing the main contactor and any transformers/inductors.
• 3. Check for loose panels: Ensure the enclosure cover and mounting screws are tight to reduce resonance.
• 4. Inspect contactor: If the contactor itself is excessively noisy, consider replacing it with an identical part.
• 5. Monitor over time: If the noise worsens or is accompanied by overheating or faults, stop using the charger and have it inspected professionally.