Cant you just hold down the ok button hear a beep and fixed.

Check your Owners Manual, it says what to do in there to turn screen back on.

I have a BA and it says to turn OFF constant screen, press and hold the Volume knob for 3 seconds until the screen goes blank, so when you adjust something on there, the screen will only display for 5 seconds after you have finished.

To turn back on, press and hold Volume knob for 3 seconds for constant display.

There is a small wire loom in the back of the ICC that go to the screen and controls like AC button on the ICC.  Sometimes they can come loose in the connector itself.  I had to take my ICC out and push down on the loom into the connector to resolve the issue of the LCD occassionally blanking out or the AC button not working on the ICC on my BA XR6T.  Been good ever since