Chosen Solution
Louis, I have a FD57 dual graphics in with a liquid spill. I replaced the keyboard. Machine runs fine except for no internal display. I saw no evidence of logic board contamination. External monitor works fine. A flashlight shown thought the Apple shows the desktop. The retinas are new to me - I only get the old sh*t to work on. On a C2D this would be the inverter. So I assume it’s something like a LED driver board but where is it and how do I fix it? Please teach me because I bought this machine. UPDATE Board# 820-3547a Pin #1 battery disconnected in Diode Mode reads 0.423 Pin #1 Battery connected & machine on reads 4.97 Pin #1 Battery disconnect & LCD disconnected 0.582
Are you sure that’s the right 820 number? I can’t find any retinas with that. 820-3787 or 820-3662 are the ones for late 2013. Hopefully this is 3787 because 3662 has nothing in terms of schematics. No diode mode measurements with power running through, it will let the smoke out! Measure voltage on pin 1 of LCD connector with it on. 0v, 12.6v, or something higher? 0v means something is gone completely, 12.6v means something is there but the circuit just isn’t boosting.
