MacBook Pro turns off after a couple of seconds

"I had pretty much same issue with a 13” MacBook Pro mid 2012.

Solved it by pulling the keyboard ribbon cable out of the ZIF socket.

Refer to step 11 of this guide:

MacBook Pro 13"" Unibody Mid 2012 Upper Case Replacement

I noticed some of the connection pins in the ZIF socket where gummed up with what looked like dust. I carefully cleaned the pins with a cotton bud dipped in alcohol. Also cleaned the connections on the keyboard ribbon.

Reinserted the keyboard ribbon. Turned machine back on and everything is now working normally."

I am having this exact problem on a 2012 15" MacBook unibody. I took it to the Apple Store and they thought it was a defective keyboard and offered to replace the top case for a little over $200. I decided to just replace the keyboard myself with one from eBay, but didn't fix the issue, still the same as before.

This happened to me too what I did was I programmed caps lock to have no function, I then taped down this key and it works like normal (I don’t use caps lock anyway) my computer is the MacBook Pro 17’ with the touchbar, still have warranty just using this as an improvision

"ok the same problem i am also facing and as Adam mentioned i inserted a toothpick in function key slot while keeping it pressed so as it remained pressed. but that is a temporary workaround.

guys check whether your serial number is available or not in ""about my mac"" section coz in my case it shows serial number not available.That seems to be the root cause of this problem.keep me updated about your serial number.

thanx"

"Update 2: The paper clip worked, but if I ever closed the lid, I had to expect it to be shut down when I opened it again. Note: what actually solved the problem was the Security Update 2019-005 for macOS 10.13.6 that I installed a few weeks ago. No joke, it’s been running perfectly fine since then, without a single random shutdown. Not coincidentally, I remember the problem first started after the previous Security Update 2019-004 installed itself. So this is on Apple.

Update: Never mind, it’s acting up again. Time to look for a new MacBook (it has other issues too, e.g. with the battery, and the left shift, ctrl, and option keys don’t work, and it’s just really old). In the meantime, I’m now trying the “paper clip crammed into the eject button to hold it down” trick.

Original comment: I had the same problem with my MacBook Pro (13-inch, Mid 2010). Sometimes it would shut down without warning. Sometimes I saw, ""Are you sure you want to shut down your computer now?"" Sometimes it would shut down during startup (holding down any key made it start up completely).

I tried the same solution as above. Opened the back panel and disconnected the battery. Found the keyboard ribbon cable and the ZIF socket (see step 11 in the guide linked above, in Scott Blinman’s answer). Lifted the socket hinge and carefully removed the ribbon cable.

Cleaned the ribbon cable and socket with Q-tips and rubbing alcohol. Blew out a few crevices and lightly dusted the logic board with clean Q-tips. Reinserted the ribbon cable. Reconnected the battery, screwed the back panel into place, and hit the power button.

It started up without holding down any key, and I've been typing this whole response without a hiccup. No need to replace the entire logic board, this did the trick!"