Chosen Solution
I spilled some liquid on my late 2011 MBP keyboard around the arrow keys a few days ago. Immediately powered it off, flipped it upside down, left it like that to drip out for about 5 minutes before I wiped the keyboard and then removed the back cover to check for internal leaks. While at it I used a can of compressed air to clean out the last year’s accumulation of dust. Wanting to make sure there were no signs of liquid around the keyboard on the inside I followed ifixit’s guide to removing the outer case up to the point where you remove the expresscard cage but got stuck with some screws that refused to turn, so I used the compressed air to blow as much liquid out of the keyboard as possible (while still upside-down) and then decided to leave the laptop open and upside-down for two days to dry out. The logic board was completely removed during this period and there wasn’t a drop of liquid on it or visible anywhere inside the laptop. I re-assembled it following the instructions carefully, and everything but the left and right arrow keys works great… except for my display. The first time I turned it on there were tiny vertical lines on the grey startup screen and all blacks were bright red, so I backed up my harddrive, did a PRAM and SMC reset with no luck, then opened it back up and removed and re-inserted the display cable. Now blacks are black again, but the display still has vertical lines on grey and generally weird colours in addition to some colours flickering. I hooked up an external display and there are no issues on that screen, just the laptop’s. Photos of the issue My laptop was fixed by Apple previously as part of the repair program due to similar display issues (vertical grey and pink lines on startup) which I was under the impression meant it got a new logic board. Unrelated but I’ve also upgraded the RAM (installed 2012) and a new SSHD (installed 2016) myself. Any ideas for what I did wrong to cause this and what I can do to fix it?
The particular video defects you describe are usually a result of a bad connection between the video cable and the board. The first thing to try is to re-seat the video cable as securely as you possibly can, and that often resolves the problem. Make sure the cable is fully seated into the connector, and that the clasp is all the way down. You can also clean the video connector and the socket, but be very careful. If none of that does it, it’s generally the video cable itself (not the board or the screen panel).
Since you get good video on an external screen it’s not a bad motherboard. Either your screen’s display drivers are having issues, the display connector on the motherboard is damaged, or the display cable is damaged. Likely not the screen display drivers; they usually go bad only when the computer has been dropped, banged around, or had a weight set on the (closed) screen. So I’ll go with either a bad display cable or display connector. Pull out your magnifying glass and examine the display connector on the motherboard for damage or dirt/moisture residue/corrosion. Clean it with some >91% isopropyl and let it dry. Check the display connector as well for similar signs of damage; GENTLY tug the wires to make sure they’re all still attached to the harness. PS: For future reference, NEVER use compressed air to blow moisture “out” of electronics. While you may get some or even most of it, you’ll never get all of it, and there’s an almost certain opportunity for some of that moisture to get blown into areas where it can create a short circuit.
