The machine is unable to operate after power failure

A. Make sure it is not caused by fuses, power switches, power cords and voltage switches. B. Check whether the transformer has nik110/220 input and ACISV output. C. Please remove the battery and turn it on with AC power to find out whether the battery voltage is not caused. (measure the battery voltage above 6V, charge if it is lower than 6V, and replace the battery if it is lower than 5.5v and run out of power soon after full charge).