Chosen Solution
I recently changed the battery on my Macbook Pro retina late 2012. The problem now is that my wifi connection is really unstable. At first I had no wifi and bluetooth at all, and found out that it was probably some issues with the i/o cable. I reattached the i/o cable again and now I had both wifi and bluetooth connection. But… After using the computer for a while I found out there was some problem with the speed and connections with both wifi/bluetooth. Can it still be i/o cable , or is it maybe the airport card/antennas – the antennas are a little bit loose.
You’ve most likely ID’ed the failed part MacBook Pro 13" Retina (Late 2012-Early 2013) I/O Board Data Cable What likely happened is you damaged a few of the contacts in the process of lifting it. Hopefully you didn’t damage the socket side on the logic board. Carefully lift off the cable and using a magnifier inspect the contacts are any out of alignment or appear bent?
