If you have connected your PS3 to a new TV without changing the settings or selected the wrong resolutions, you will sometimes get a blank screen.
If you can’t access the [Settings] menu to reset the display, turn off your PS3 and then hold down the power button for 10 seconds. You will hear two beeps and then see something on the screen. Holding the power button down for 10 seconds will reset the display to the lowest settings and also restore some other settings to their defaults.