hello
i have an Acer E5-571G A5WAH LA-B991P with black screen. BUT it works on External VGA
checked the LCD and cable!
Reballed the GPU!

i have tried these BIOS dumps but none of them work for me. with all bios dumps other than original i get power on after pressing the power button, but to image, not even on VGA like with the original BIOS

i have tired this:
viewtopic.php?f=232&t=120188
http://vlab.su/viewtopic.php?f=59&t=6507&start=280
http://www.badcaps.net/forum/showthread.php?t=54389

any ideeas?

Find schematic and try to modify board to UMA.