Chosen Solution
Hello, I had my logic board changed under Apple’s extended repair program in 2015 when it was still relevant for 17 inch MacBooks. 2 years later, during autumn 2017 my (replaced) logic board stopped working again. Not being covered by warranty or any repair program anymore, I had to resort to baking my logic board and hoping for the best according to this guide. Fortunately, it helped and I was happy I had saved some 200 bucks on new logic board. After reassembling and starting using my repaired MacBook I noticed that the right fan was making weird buzzing sounds, very similar to this one. It is interesting that when I apply pressure to this part of the MacBook’s body, the buzzing sound instantly disappears. Soon, I noticed the D, F, G, H, J, K, L keys growing non-functional. During the time when they keys’ non-functioning was intermittent, either none of them was working or all of them were. Any advice please?
did you bake the full board or did you just heat the gpu. also when reapplying the heat sink did you ensure the screws were tight to prevent any vibration and the same with the fan. for the keyboard I believe you may just need to reseat the ribbon cable, maybe you didn’t reseat it all the way in. give it a go Ann let me know how you get on.
While I think the issue is most likely a hardware issue, It would probably be worth it to try an SMC reset (https://support.apple.com/en-us/HT201295). If the issue persists, open up the MacBook one more time and inspect the ribbon cable connector pins for any damge/dust, as well as the logic board for anything that looks out of place. Let me know if any of these methods turns up anything helpful.
