Use the [Fn] and the [Fx] that is assigned with a Monitor look. You have to Press both at the same time. Make sure press 1, 2, 3. LCD display can go dark if press. That is one way you can recover. Also Check the dimmer (bright and contrast) buttons might causing it. If you really have tried everything then the Panel has gone DUFF (means bad) This would need to be replaced by a service tech. Really you could do the work just have to make sure you keep all the tiny screws that are required to be removed and then place back in the order it was taken off. Takes time but if now right you could fix your own issue.
Best bet is to try the second reply and what happens?
