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My aluminium unibody 2008 Macbook has two audio issues. First of all, the internal speakers are damaged, they are very silent and start distorting a lot as soon as I turn the volume higher. Optical out and headphones still work like a charm. The Apple service said I got to change the logic board. No, thanks, not for this cost… :) The second issue is the common one, that the audio jack frequently jumps back to “Internal speaker”, disrupting the sound via headphones. As I cannot use the internal speakers at all, I would like to disable them by some tricky soldering on the logic board. I want to be able to switch between Optical-Out and Headphones-Out. Does anyone know how to do this? I could not find a explanation for the contacts of the audio jack on the logic board. Can anyone help how to do this? Thanks a lot in advance. Martin
The easiest way to disable the speakers is to simply disconnect then from the logic board. (Link provided) As to your second problem I would disable the internal speakers and see if I still had the problem. Good luck. MacBook Unibody A1278
You may also need a new set of headphones as the connector just don’t fit quite right into the socket. Look at an Apple set and look at yours note the total length as well as the detent (the thinner point just behind the tip). Some are slightly short or the detent shape or location is not quite right. The socket has a switch which as others have pointed out does get damaged. If I remember correctly the switch closes to enable the internal speakers. In your case you may want to pull the logic bd out and solder a wire across the socket switch so the headphone socket is always active. Otherwise you’ll need to replace out the logic board to get the socket working. If you can find a dead system for parts you might be able to swap out the socket.
With it jumping back to the internal speaker, i believe there is a bad connection on the audio jack, either where it connects to the headphones, or where it is soldered on the board (or flex cable, however it is attached). Especially if you can wiggle it. Also with wanting to remove the built in speaker functionality, why dont you just remove the speakers all together. Desolder them? Should be fairly cut and dry….
With some of these units and past versions of the MBP, if you carefully use a paper clip stretched open and put it in the headphone jack and carefully use it to manually turn the part which senses if the sound is input or not it will sometimes clear the issue. It may have to be done more than once or it may not work but occasionally it does solve the problem.
