Keyboard and trackpad not working.. Macbook Air.. FIXED :-)
I have had this same problem occasionally, but I do believe that most of the posts in this forum are basically the same problem for the most part, that show up in various degrees of seriousness depending on the each machines' individual situation. Which is why different fixes work for different peoples machines.
I would like to say thank you to all the contributors to this forum, because using most of the tips has helped me to solve my machines problem. (At least for now) ;-)
Sequence of events that happened in the situation with my machine:
Machine is the first version of MacBook Air from 2008.
Processor 1.6 GHz Intel Core 2 Duo
Software Mac OS X Lion 10.7.5 (11G63)
Model Identifier: MacBookAir1,1
1) Had no problems at all until the original Factory installed apple battery
decided to expand and swell the housing of the keyboard and trackpad.
(But the machine is 8 years old. Not sure this is an excuse though.)
2) On occasion, where the said problem, my keyboard and trackpad both
become unresponsive. I just looked inside the case and ensure that all ribbon
cables with a connector on the end were pushed secure.
And Voila, when rebooted the machine booted ok, and the keyboard worked for
sometime. (Note: there were no messages relayed on the screen at this time
3) On a different occasion, the same problem occurred, but this time a message
came on the machine while booting that mentioned a bluetooth keyboard and
mouse, which i never had connected at all. (note: Somebody else mentioned
that in the System Preferences, it's not even recognizing a trackpad as being
connected and thinks there is a bluetooth keyboard trying to connect. (I believe
that this behaviour is a symptom of the issue) The only button that worked on
the computer was the power button.
4) As an engineer myself, i have seen all kinds of issues with computers which
don't appear to be logical when trying to fault find.
Now, after it happened the second time, rebooting and pushing cable
connectors didn't work.
So I decided I needed to figure out whether the issue was a hardware problem
or a software problem. So i decided to checkout some of the tips from this
5) Decided to Reset the PRAM
a] Resetting NVRAM / PRAM
I) Shut down your Mac.
II) Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
III)Turn on the computer.
IV)Press and hold the Command-Option-P-R keys before the grey screen appears. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
V) Release the keys.
b] Also performed an SMC reset whilst booting the machine:
c] Turned Bluetooth off. ( I thought this might be related to the bluetooth message that comes up while booting)
d) Remove all EXTERNAL cables from machine and reboot
6) NONE of the above in step 5 worked, but i understand why they might work for others.
Note: While going thru all this testing, I realized that rather than wait for machine to boot up to check whether the keyboard and mouse will work, all you need to do is PRESS the CAPS LOCK button, as the green light won't come on if the keyboard is NOT CONNECTED/WORKING.
I still let it boot up, but this indicator was apparent.
7) So now I am thinking that this is a hardware problem, that in effect also shows up as a software problem. i.e.: If the ribbon cable or a short circuit/open circuit in any of the wiring or circuitry is apparent, then this will affect the way the motherboard/bus and software interact.
(This is why I believe the whole bluetooth message shows up while booting)
8) I ran diagnostics. Hold down 'D' on keyboard before grey screen shows up. (Not sure which versions of Mac OS this still works on, but it worked on mine. Mac OS X Lion 10.7.5 (11G63). The diagnostics came up with an issue.
Here is the message:
Alert! Apple Hardware Test has detected an error.
9) Finally i decided, that the problem is on the left side of the machine close to the where the battery ribbon cable plugs in. Why?, because while booting the machine I decided to GENTLY press the cable connectors on the left side and the the board itself, which suddenly brought the trackpad to life. Then when i stopped pressing, the trackpad stopped responding. Now i am not sure if any of the circuitry has dry joint or a ribbon cable had a broken wire or if a short circuit on the board occurred. But what i do know is that it is definitely a PHYSICAL hardware issue.
10) I repeated the exercise of pressing the connectors etc in STEP 9 since the problem didn't go away and on the first occasion. This time the Trackpad and Keyboard continued to work.
I believe one of 3 things happened.
a) There was some kind of dry joint and by pressing the circuitry, the joint became more stable and allowed current flow, therefore acting as normal.
b) Some part of the circuitry was shorting, and by pressing the board/connectors, the short was released.
c) One of the connectors was intermittently disconnecting and by pressing the connectors a better connection was made, therefore the circuitry performed as normal.
11) The complexity of circuit boards today and the amount of heat that is present around that side of the machine could indeed lead to circuits malfunctioning intermittently, which is why some of the solutions that others tried actually worked. In my case the last attempt of pressing the left side of the circuitry and cable connectors has been working for 24 hours. But I do believe that the situation could and probably will happen again. But i hope it doesn't.
I use my machine on while travelling so it does get moved around quite a bit, which could cause something to move within the machine that recreates the problem.
12) As a side note. Dry Joints are well noted to cause this type of intermittent problem, as when the dry joint occurs, it means a part of a circuit will not be functioning as the joint becomes open circuit which can have a plethora of different outcomes, depending on which part of the circuit is affected.
Hopefully, this will help others with their issues. But remember never to add lots of heavy pressure when doing any of the above, otherwise the board could break so gentle is good.
13) FYI: Since everything has been working, I decided to run Diagnostics again, and guess what?
Test Results show
No Trouble found
So this now makes logical sense. The issue has been resolved at least temporarily, and the Diagnostics prove that.