In this post I explain how I fixed the trackpad and keyboard after water spill on a MacBook Air. The trackpad and keyboard stopped working completely after a very minor spill somewhere in the area of the spacebar.
Everything else in this MacBook Air kept working fine like the water damage has never happened. An external keyboard and mouse connected via one of the USB ports also functioned properly.
First of all, I removed the bottom cover to do visual inspection of the internal laptop components. For removing the bottom cover you will need a special P5 Pentalobe screwdriver.
Two screws I marked with green circles are longer than other eight screws.
After removing the bottom cover I disconnected and removed the battery to take a closer look at the trackpad area. For removing the battery you will need a T5 Torx screwdriver.
Again, three screws I marked with green circles are longer than two other screws. Pay attention during the reassembly process.
I didn’t find any water damage on the logic board. No signs of oxidation or corrosion.
In order to troubleshoot a problem like that you have to understand how the signal goes from the keyboard and trackpad into the logic board.
In a Macbook Air the keyboard is not connected directly into the logic board. A signal from the keyboard travels into the trackpad (red arrow), after that it travels through the trackpad circuit board (green arrow) and eventually goes into the logic board though the trackpad cable (yellow arrow).
- If the trackpad still works, but the keyboard doesn’t, it’s either bad keyboard which has to be replaced or there is a failure in the chain somewhere between the red arrow and green arrow.
- If the trackpad acting weird (the pointer moves on its own, moves erratically, clicks by itself) but the keyboard still works, most likely it’s just a bad trackpad and replacing it with a new one will fix the issue.
- If both stopped working at the same time (like in my case), you’ll have to take a closer look at the cables and connectors in the red-green-yellow chain.
There are three connections in this chain:
- Red rectangular- connection between the keyboard cable and the trackpad circuit board.
- Green rectangular – connection between the circuit board and the cable.
- Yellow rectangular – connection between the trackpad cable and the logic board.
My troubleshooting steps
I disconnected the trackpad cable from the logic board. In order to release the cable you’ll have to unlock the connector by lifting up the locking tab (red arrow) and after that pull the cable out.
Be very gentle because it’s a fragile connector. The locking tab can be easily damaged if you apply too much force.
After that I looked very closely into the connector and found some evidence of the water damage inside. There was some light blue residue on the golden connectors. You’ll see on the last picture what it did to the cable.
I very carefully cleaned up the bluish residue on the connector pins using a soft toothbrush and 99% isopropyl alcohol.
I disconnected the cable from the trackpad and inspected the connector. I didn’t find any water damage in there.
I removed the trackpad cable and set it aside for later.
The last connector to inspect was for the keyboard cable. Releasing this cable can be a little bit tricky because the connector is hidden under the cable.
Again, unlock the connector first (red arrow) and pull the cable out. I didn’t find any damage inside this connector either.
After inspecting all the connectors, I moved to the cables. The keyboard cable looked clean and undamaged.
Now it’s time for the trackpad cable.
The end that connects to the trackpad looked great. All golden traces were intact and undamaged.
The end that goes into the logic board, on the other hand, didn’t look healthy! You’ll have to use a microscope or magnifying glass to insect those traces.
As you see, in my case two traces on this end of the cable were corroded and burned.
In MacBook Air laptops this cable is a very common point of failure. There is some voltage running through the connectors and when liquid gets inside, the cable traces get damaged very easily.
I was able to fix the trackpad and keyboard issue in my water damaged MacBook Air simply by cleaning up one of the connectors and replacing a $7 cable.