Flickering Screen Problem!

could you give more details on when this happens? does it happen when you ride in the dark, or indoors? Did you had a crash which might have caused a component to "come lose" (connector)? 

Perhaps it is possible to disable the automatic screen brightness and set it to manual. 

I have mine set on automatic and I had similar issue, however I found that it was only when I rode in the dark. I saw a pattern emerging while riding underneath street lights. The light sensor picked up the streetlights and adjusted the screen brightness according to these light sensor readings. 

Same here. I cant go into the menu to make changes

Because the screen in dark

If your screen is dark and you only see a blank screen even in daylight - without recognising anything on it, then it is not due to the backlight, but rather your Edge is not working at all.

I did all the reset options. The screen will come on but not enough time to go to menu etc.

Try to connect your Edge to your PC/MAC.
Backup to your harddisc and delete on Edge all files in
/Garmin/Newfiles
/Garmin/Activities
/Garmin/Courses
/Garmin/Segments

Parallel question. Is it safe to delete the Garmin Light app? I would like to control my lights with the Trek light app.