Chosen Solution
I just replaced a logic board on a 2009 A1278. I bought a tested board, and it’s guaranteed. But, I think my issue is a little 3 prong snap down cable. It comes from the back near the hinge, and snaps onto the logic board like a fan connector. What is this for? Would it cause a no-boot? I don’t even get a chime, screen. Hard drive lights up, fan runs and thats it. The only issue I could find is that little cable. One if the gold connectors came out of the connector. Ideas? It runs from the hinge all the way to the front, underneath the board. Very odd cable length and placement. Stumped! There are bare wires where the snap down connector was, it was stressed really bad.
I think it’s the mic cable? What do you guys think? But, why does it go into the monitor channel bar?
The end connector looks just like this, accept it’s freyed. That certainly shouldn’t stop it from booting. I’m going to try an external monitor, and get back to you. But why no chime? I’m still confused!
Yes, that’s your microphone and having it missing will not cause booting issues. See step#24 of this guide: MacBook Pro 13" Unibody Mid 2009 Logic Board Replacement
@thomhemler & @mayer You appear to have some other issues as well! The SO-DIMM appears to have a burnt mark on the contacts as marked here
Using some isopropyl alcohol might clean it off but you may need a fresh pink pencil eraser (still soft) to clean it. You could also have issues with the socket. You at least can try a different SO-DIMM. Looking at the other image I see corrosion! If this is a replacement board it might not work!
