Backlight / screen problem
MacBook Pro a1502 - 2015
I have a weird problem.
I replaced a logic board on a MacBook a1502. Year 2015. Problem. Was liquid spill, on the bad board everything would work when plugged in , but it would not work on the battery.
I replaced the logic board , and everything was fine. Few days later Customer dropped laptop while it was on from sofa. Nothing was fiscally broken but the screen went black ,.
It works on a external monitor through HDMI ,
The backlight of the LCD actually comes on, but it only comes on after boot, but no display. During boot cannot see apple logo even if I put light to it.
So, to check if was board or screen I took the old board which was still working ,but only plugged to power, and same problem happened. So I thought screen is bad.
Order new screen assembly, installed it, now I get no backlight at all , I can see apple.logo during boot, the desktop icons and everything but no backlight at all..
Took the old board, installed it ,same problem.
This is driving me nuts, could it be that the bad screen had some kind of short and it actually damaged both boards ?
Or maybe the new screen I got, is a factory defective unit ?
Thanks for any suggestions