Cannot get the phone to turn on. The battery is fully charged. I tested it with my multimeter plus it has been charging for a day and a half by now. I examined the mother board and see no burned out electronic parts either (visible to naked eye defect search). The phone still identifies itself as the #1 of the two handsets (HS1 on the screen), but no response when any of the other buttons are pushed whether in the charger or picked up and held in the hand.