I have a Dell U2717D that has been flashing colors between black, white, red, green, blue in sequence. I power cycled. Tried multiple connection methods over Display Port, Mini Display Port, and HDMI. Unplugged all cables and held down the power button for 10 seconds. Made sure none of the buttons were stuck down. It does not matter if the monitor is connected to a PC through any kind of display cable or not, it does this at all times, except it does appear to enter sleep mode still. None of the buttons are responding with the exception of power. It does not allow me to bring up any menus or exit. It does not manually cycle the colors if I hold the first button. None of the buttons appear to be stuck in anyway from what I can tell. Does anyone have any additional suggestions?