EFB is not working

[feng nuan]

EFB 不工作。我已按下电源按钮，但显示屏不亮。

[Dave Barton]

It is very dim.  Turn the brightness up with the rocker switch to the right of the power button.  Same issue with the WX radar, but even at 100% brightness it is barely readable.

[Veteran66]

as Dave Barton wrote it, look the EFB is on and more than 10% brightness