On occasion, my partners 2011 MacBook Pro has the issue described in the title. I would characterize it as recurring because it happens every month or so and the computer has to be turned off to solve the issue (power button shut down). She did spill a glass of water on it a couple of years ago and Apple warned us that we could see problems one day because their was logic board corrosion. I'm interested in fixing this issue and have two questions for those with experience: 1) In Canada, what does a new logic board cost for the i5 model? I suspect this is the likely issue because both our computers run 10.9.5 and mine has no issues. 2) On Kijiji, this computer sells between 600 and 1200 pending the modifications. Since this one is stock, I'd put it around the 800 range, maybe lower since she has done a poor job taking care of it (dent on the bottom, noticeable scratch on the lid, and of course the water). Does it make more sense to wait for a logic board failure and replace or sell as is? Thanks for any help.