DIAGNOSIS A flashing charger light indicates a communication fault, usually caused by dirty contacts or a battery that’s deeply discharged or faulty.
FIX First, clean the gold charging contacts on the vacuum body and the dock with a dry cloth. Ensure the vacuum is seated correctly on the dock. If it still flashes, try charging the battery directly by plugging the charger into the port on the battery itself (if your model allows it).
IF THAT DIDN’T WORK The battery may be locked. Remove it from the vacuum, press and hold the power button on the battery for 10 seconds to reset it, then try charging again.
HEADS UP Leaving a fully drained battery uncharged for weeks can kill it permanently—Dyson batteries don’t like being stored empty.