Hi everyone, I have A1398 Late 2013 Laptop that has no video on internal display. Tried many tricks to no aval.
Originally this laptop had water spill and one of the chips had to be changed to get 3v3 to display lvds connector.
Also EFI chip was replaced and I have a feeling that EFI is not fully compatible because I can get video on external display every time it starts,
but internal screen starts only after PRAM reset. Once display is on, laptop works 100% it can go to sleep properly, wakeup without problem,
if I restart everything works and display works as it should, but if I select shut down, next time I press power button screen will not light up until PRAM reset.
I hope I make sense. Thanks in advance.