I had the same problem for a SA300, Ive tryed every solution on the web but finally got the real one by accident, press three buttons at the same time, menu, down arrow and up arrow, the monitor will blink after a few seconds, then use the down arrow to change the brightness and wait 10 seconds to see if it was succesfull, if not press again and let it blink two times... I hope this help anyone with the same problem...... sorry about my english I'm from Peru and I do speak spanish