Daughter has same model with same problem - runs for one second, then stops. She had replaced the battery which resolved the problem for a while. It is now experiencing same issue. Using a meter, I determined that the charging cord is working properly but the wires to the battery are not providing power to the battery to charge it. I opened the unit and found a circuit board under the switch; will add pics. Assuming the board provides battery charge monitoring, I bypassed the circuit and charged the battery for an hour (battery got slightly warm, but never hot). When I removed the bypass and tested the unit, it continued to run until I turned it off. Circuit board is too complicated for me to troubleshoot - a two-sided surface-mount board.
Daughter has same model with same problem - runs for one second, then stops. She had replaced the battery which resolved the problem for a while. It is now experiencing same issue. Using a meter, I determined that the charging cord is working properly but the wires to the battery are not providing power to the battery to charge it. I opened the unit and found a circuit board under the switch; will add pics. Assuming the board provides battery charge monitoring, I bypassed the circuit and charged the battery for an hour (battery got slightly warm, but never hot). When I removed the bypass and tested the unit, it continued to run until I turned it off. Circuit board is too complicated for me to troubleshoot - a two-sided surface-mount board.