Hi, I've got a mid 2012 15 inch macbook pro, with 16gb of RAM bought from crucial that has been working fine since then. the 512gb hard drive is the one that came with the laptop. The other day it wouldn't boot up. I took it to the genius bar and they said it might be to do with the logic board, which would cost around £500 to replace. I managed to run the hardware test and it came up with the code 4mem/62/40000000 which is apparently a memory problem. I replaced the memory with a different 16gb of crucial matched RAM to no avail. I've taken the laptop to an independently run apple repair shop, and they've said the RAM is faulty, and the laptop should only take 8gb of RAM (which I know is not true). They also said the hard drive is faulty, but not completely broken, just running slowly and needs to be replaced. Do you think it's possible that the RAM is fine and it's just the hard drive which needs replacing? Thanks, sorry this is such a complicated and possibly unanswerable question.
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