Thin white dashes on top of screen is PERFECTLY NORMAL. It is nothing wrong with the TV, it is the broadcast. What you are seeing is the very bottom of the timecode running. It doesn't happen all of the time or all channels. It usually happens with old 4:3 commercials predating "Digital TV." This is mentioned in your Users Manual. You should be able to adjust the horizontal/vertical position in the menu settings.
You know, I've had two repair instances regarding this particular model line (D64U) where there were problems with only the analog inputs (such as the component/composite).... but with no problem with the HDMI inputs.
Replacing the Main Board fixed these TV's. Since both the Xbox and the Wii present the same problem on two separate inputs, this leads me to believe you most likely have a defective Main Board. If your TV is still under warranty, I suggest calling Sharp to locate your local authorized service center.
Set comes with at least 90 days labor and one year parts warranty----new or refurbished unit?
Have you check all inputs as the HDMI inputs and the composit inputs are processed on a different bd?
I have the same problem with my 37" HP which is the same as Sharp Aquos, it's bad backlight inverter boards, the screen comes on for a second then nothing, no menu, no channel change indicator then turn it off and you hear the clicking of the power supply about 10 seconds after.
Didn't expect this to work at all, but it did, thanks!