Hey there, i4doconly here! had the same issue... so my man & I tore a broken screen down to see internal guts so we could find a solution for our lap. Now we discovered the older screens have florescent light bulbs that are very slim and line the squared interior frame...  So in conclusion i found out that the screen illuminates with the light but if broke, it wont light it will be black, so try shining a flash light directly onto the screen and if this don't answer, please send e-mail im4doconly@yahoo.com & we'll figure it out!