thanks for you reply. i have the Mark l no i didn't swap batteries and here is why. The unit now is illuminatingly the info window but without any text or info of any kind. Totally blank, but illuminated. the clicking sound of the rotating dial is there. will not work as in dial tone or any other function. do you still think i should switch the

i have three of these great beauties. last night one mysteriously stopped working...doesn't show any signs of life. The Battery is good, but i can't get the unit to come on... CAN SOMEONE HELP!