Chosen Solution
So this is the story: I have some keyboard key’s that aren’t working. I changed the keyboard but still the same buttons are nlt working. I can see on the motherboard that i miss some components.
whats the solution? Update (09/20/2020) Yes it’s ‘820 2850 A’ :D @oldturkey03 Update (09/20/2020) Good question! I took a picture. The red ones
@melkhalfi To clarify, these components are not populated in production systems as you can see here:
So this is not your issue. Can you fill us in on what’s going on which keys are not working? Update (09/20/2020) The keys you marked share three column lines: The first being the 9, O, L as well as the colon keyThe second being the 0, P, M and equals keyAnd the third is the accent, return & arrow keys. This is common problem when there was a liquid spill which has damaged the keyboard switch lines under the keyboard keys. Basically, you have a grid of X lines and Y lines and the key shorts across these two lines to create a circuit the computer understands as a given key symbol. Sadly, there is little you can do to fix this other than replace the keyboard unit MacBook Pro 15" Unibody (Mid 2009-Mid 2012) Keyboard its a bit of a job as you need to strip down the uppercase to get to it, here’s a great Youtube guide: 2009 Macbook Pro 15" A1286 Keyboard Replacement which is the same process for your system.
If you’ve changed the keyboard and the fault is still there then the issue is clearly the logic board and that should have been obvious. You’re issue is likely the keyboard connector pins are bent and needs a new connector soldering(very delicate work) or liquid damage corrosion to a joint or probe point which can be fixed with enamelled jumper wire.
