The 2 "buttons are NOT physical buttons, they are touch sensitive sensors. DO NOT PUSH, just lightly touch. The other odd and repeatable "malfunction" is attempted operation while the cord has a few coils in it. For instance.... The wall outlet "mains" is right next to the rear of the car where the charging port is located. I plug into the wall, leave the cord coiled in the rear hatchback area just to keep it off the ground, then plug the evse into the car. It fails sometimes if the cord is looped on the hanger too many times. The unit will NOT start now, or ever if the cord is coiled. I strech out the cord and it works 100% all the time. It does not make any difference if operationg on 120 or 240 volts or which level the charge current is set for. Other than that, GREAT inexpensive evse. Operation at full power the box will get warm.