I was in the middle of taking pictures when the D90 just stopped working. No screen. No warning. No battery level. No picture count. Nada. I've taken the lens off and put it back. I've taken the battery out (it still had most of a charge when last I looked) and put it back. I've pressed both green marked buttons (held down for as long as 10 seconds) at the same time. Nothing. Am I toast? Do I need a Nikon service center? Does anyone know of one in Phx/Metro area?