Display shows E03, and the mower will not leave the charging dock; sometimes accompanied by a plug or lightning icon.

Safety: Disconnect the dock power adapter from the wall before touching any metal contacts.

• Verify AC outlet: Plug another device (e.g., a lamp or phone charger) into the same outlet to confirm it has power. Reset any tripped breaker or GFCI.
• Check dock adapter: Inspect the Yarbo dock power adapter for damage, a frayed cable, or a burnt smell. Ensure the LED on the adapter (if present) is lit when plugged in.
• Inspect charging contacts: On both the mower and the dock, clean the metal charging contacts with a dry cloth. If there is heavy oxidation, lightly polish with a fine Scotch‑Brite pad; do not use water or aggressive chemicals.
• Reseat low‑voltage plug: Ensure the low‑voltage plug from the adapter is fully inserted into the charging dock input jack.
• Test with another outlet or adapter: If available, test the dock on a different outlet or with a known‑good Yarbo power adapter.

If E03 remains and the dock has no output, the dock power supply or internal dock PCB likely needs replacement.