Chosen Solution
Hello iFixit! Around a year ago I’ve got coffee spill over my MacBook Pro mid-2015 15". I dried it out, and stocked in on a shelve and almost haven’t touched it since. it is almost unusable. This is a very nice high end (Haswell) machine with 16GB of RAM. The issue I’m experiencing is “come and go”. Sometimes you can use it for an hour without an issue but sometimes the screen starts to turn on and off, sometimes rapidly, and sometimes slowly, frequency is changing. Lid close is not detected. and the device is not going on sleep mode. I suspected the Hall sensor located on the side of where the coffee spill was, and indeed it was a bit dirty. (attached before and after my cleaning). However cleaning it didn’t make any difference. those becoming stronger or weaker, but never goes away for more than several minutes. Also when connected to an external display - it is unusable as the screen is like shut and open all the time. Any ideas?
Looks like you’ll need to do a bit more cleaning around the smaller SMT devices. Use a soft toothbrush with some distilled water, then go over the area again with 85% or better Isopropyl alcohol. The problem you are likely facing is the raised sensor block maybe damaged which carries the signals from the lower board up to the Hall sensor transistor. This may require a new board to fix.
