Backlight flickering, what do i do!

[nuthineasy88s]

Hello all, I'm new here but not to electronics so much. I just bought a mogul (privately, no warranty) and the back lighting will flicker off and on. It stays normal if you do not go past the second bar on the slider but if you go past that it will go to that brightness for a second or two (completely random) then flickers and goes back to no back lighting and sits there and flickers like it's trying to go to the correct brightness. Does anyone know what I need to do? I have the stock ROM (newest version) and have only done the custom slider sound edit. It did this before any of that though so it should not be that. I'm thinking it's the screen, anyone know for sure?

Thanks for your help guys, I really need it. I love this phone and don't wanna have to go back to my old one.