Chosen Solution
The keyboard & trackpad on my macbook stopped working all of a sudden. I opened it up to investigate and found a very suspicious grease stain by the keyboard. It seems to have been caused by something inside the macbook. Any idea what this could be from? I don’t think it’s causing the keyboard issues but just curious whats spewing oil on the inside… EDIT: my computer overheated during normal use, and smelled like electronics cooking. It had never happened before so I turned it off. Shortly after, it had trouble detecting the keyboard, so I assumed the events were related. However I could still enter my password on the login screen - the keyboard stopped working only after login. So I suspected a software/driver issue. I booted into Safe Mode using a usb keyboard and everything worked fine. This confirmed my suspicions. So I decided to wipe and reinstall the OS. Now the keyboard doesn’t work at all. So I’m back to suspecting a hardware failure. Also this computer is of low value to me. I’m mostly interested in understanding what happened and learning how to fix it out of curiosity. Maybe I can donate it to someone who needs it if I fix it.
I can’t tell from the photo. A leaking heat sink will cause a greasy type of residue stain. See if your stain is adjacent to the crimped ends of the heat sink. If so, replace it. I can’t tell from the teardown if this machine even has one.
The only liquid would be an electrolytic capacitor failing, there just isn’t any in your system. It’s more likely a stain created during the the manufacturing process. As to why your system keyboard & trackpad have stopped working will need some deeper diagnostics. Do you have a bluetooth keyboard and mouse which you can sue with your MacBook? If you can see if you can check the USB section in the System Report, do you see the hub and the internal keyboard and trackpad?
