Chosen Solution
Hi guys, I’m getting ready to order a new display, but wanted to clear up some final doubts before doing so. The internal display comes up completely black, and as a computer tech, I’ve tried everything I could find (PRAM reset, SMC, physically unplugging battery and display cable and replugging after a couple minutes), etc. Not even with a flashlight could you see any faint image on the internal display. On the external display, the computer shows and works just fine. I feel pretty confident that I just need to replace the display assembly, but before doing so, what are the chances that this could end up being logic board related, and my purchase ends up needing to be returned? EDIT: This model is a 13". I found a couple cracked screens I still had lying around from previous repairs. I’m not sure exactly which macbook they came out of, but one was 13 and the other was 15. Both show up black when plugged into this machine. The 13" does seem to flash for a second, and does it again after it’s been on for a little bit, but nothing else.
Try removing the assembly, the hinge cover and reconnect the backlight cable and LCD cable from the screen side. I had a couple like this before which were just resolved through reconnecting the screen internals. If you know the 13" broken screen you tried is working, it will be logic board related. I would recommend getting a board view and schematic, and measure voltage on the backlight fuse (think it’s F7700 on this board) and pin 1 (haven’t got schematic in front of me, but one of the early pins) on the LCD connector if the fuse gets power (all with the screen plugged in). You will then have to follow the schematic to find out what is causing the issue. It’s more difficult to tell if these models are no backlight or no picture.
