Keyboard and touchpad not working at all.
So I am at my wit's end. I have been trying to refurbish an old MacBook air however I am having some difficulties. Namely, both the keyboard and touchpad are non working. They are not even seen by the operating system at all. I have entered settings to look for them and they are not even shown. (all of this came about when trying the fixes that relate to sticky keys and also bluetooth overriding the internal hardware.
I can do a SMC reset using the shift+control+option+power and the backlight works, however nothing else (barring the power button itself) works at all.
I have taken the MBA apart and checked the logic board for any water damage, (none of the indicators have turned red), and I have used isopropyl alcohol to clean all of my ribbon cable connectors before reseating them but to no avail. (Wether the keyboard itself has water damage is unknown.)
I even worried that it was the battery swelling and pressing up with against the top of the casing, but the problem persisted even with the battery completely removed.
Other things of note regarding this device, I am currently running my operating system off of an external hard drive, using a Sata to usb converter, and that operating system is updated to macOS Sierra 10.12.2.
Regarding the external drive, this problem also manifested itself when I was using Ubuntu Linux via a usb drive.
I am going to try replacing the touchpad next in an attempt to insure that that pcb is not the issue, after which I will be looking into replacing the keyboard itself. Honestly I am just trying stuff to see if it sticks at this point.
Have any of you seen this?
Any help is appreciated.