Replaced MBP late 2013 logic board with early 2014 - Not recognising

Hi Ian, thank you for your reply. I think that the trackpad cable is seated correctly, as it still works with my old logic board. The issue I have is that the new logic board is not recognised.

From what I have been reading this evening, the part number (820-3476) for the new mid 2014 board matches the old late 2013 one, but, I believe that the new mid 2014 board might have a different EMC? My old board that I removed is Model: A1502 (EMC 2678) and ID: MacbookPro 11,1 - whereas the replacement might be Model: A1502 (EMC 2875) and ID MacbookPro 11,1. There is an equivalent upgrade from late 2013, with the same EMC number as my original logic board. Would this matter? I'm thinking of replacing the keyboard again first, as I assume its lack of connection could influence the trackpad? However, the main issue is that the Mac still believes that it has the old logic board inside, despite me fitting the new one, as it is showing the old logic board information on the 'about this mac' screen?

Sorry, I misread your reply. I will open up the mac now, but in order to reset the SMC, I need to get the keyboard working again. Any idea on how to reset the SMC with a windows keyboard? I do not have a power button on it.

OK I'm confused now!

You stated the trackpad was not working, now you are telling me your keyboard is not working as well??

To clarify your confusion on what logic boards are workable in your system forget EMC! Focus on the ID here we are looking at this group of systems MacBookPro11,1 Apple used the same hardware across this series of systems. Boards in this listing will fit and work.

Hi Dan, in my original post, the addition of the information concerning the trackpad and keyboard not working were an afterthought, in the consideration that they may possibly be related.

In summary...

- I upgraded the logic board for a necessary replacement

- The replacement logic board was the correct ID (as per your link)

- The mac is now working and not shorting out

- The fan issue is resolved too (no longer running full throttle)

- However, the CPU of the replacement board is operating at 300%+ (supposedly) and throttling the system speed.

- The mac is not recognising/showing the new board information under the apple logo (top left) > 'system information' (old board information is still shown, despite being replaced)

- It just so happens that the trackpad and the keyboard are now no longer working either, despite multiple reseating.

I've re-read my original post and can see the confusion. Apologies for that, I hope this is clearer?

If both your keyboard and trackpad are not working then you have a bad replacement logic board or you have deeper issues within the upper case likely liquid damaged keyboard and trackpad.

Your system is doing what its designed to do!

Think of it this way... Your office building has a fire alarm system (your systems SMC logic) what happens when someone sets the bath room waste can a blaze? The detector in the bath room fires off and then ALL of the alarms across ALL of the floors go off, everyone gets up and out the nearest exit. Nothing is being done.

As I stated before SMC is in Fire!, Fire!! Mode so nothing can happen until the SMC logics problem is resolved.

You need to fix your keyboard and trackpad issue to clear the error condition so SMC is able to work properly. Until you do that SMC is not going to refresh your systems info held in your OS.

OK can you prove this? Yes! Open Activity Monitor App You'll note the kernel_task process will be consuming all of the resources!