HDTV and HDMI..Dish DVR problems

I recently upgraded my Dish satellite from an 811 HDTV receiver to a 622 HDTV DVR. During the setup the tech pressed the select button for the incorrect resolution of 480P. My Tv is A Sony Grand Wega 55KDF-XS955. The receiver was connected to the tv through an HDMI cable. The tv's pixels blacked out and now the tv display is pure white and I cannot get access to the other inputs or menus. What could have caused this bizarre behavior? I have tried to reset the tv but with no luck. Thanks, Bhome.