Switch off LCD backlight

NETMF & Gadgeteer
1

I switch off the screen after a certain period of inactivity in my app.

So, after 5 minutes, the screen is erased with a black color but I can see in the dark that the backlight of the LCD is still active.
Is someone knows how to switch it off ?

Thanks.

2

There is ADJ pin on LCD board that you can wire to any pin on fez to power down. See schematics please