Random Keys Working Sporadically

I have a MacBook Pro OSX, that I bought about 4 years ago. It has worked PERFECTLY for me. Until now. What is happening is at RANDOM times and for RANDOM lengths, a few keys (t,y,u,i,o) will STOP working. It is totally random and there seems to be no pattern to it at all - they simply will work, and the stop, and then work again (as you can see, they are working NOW). I brought it in to the local computer shop (Best Buy) and they did a hardware analysis to see if the keyboard was broken. It came back and said the keyboard was functioning fine. I don't know what to do at this point?? I've read about the battery perhaps swelling up and causing this, but IDK...ANY help would be GREAT!!!!

MacBook Pro, OS X Mountain Lion (10.8.5)

Posted on Mar 10, 2014 1:32 PM

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Posted on Dec 3, 2014 12:12 PM

So I thought I'd weigh in here to explain how these keyboards work:

User uploaded file

This is the contactor array of a MacBook Pro 2011 13" . You're looking at it from back to front. Those round dots are where the silicone rubber "cones" cause the front array to make contact with the back array, telling the computer which key has been pushed. The width of these (I think deposited silver ) traces is about 0.5 mm.

User uploaded file

Now you're only looking at the just the front array. You can see that the contact pads are connected in series. A break anywhere in the trace connecting them would cause the "downstream" keys to stop working.

User uploaded file

So here you see a site where galvanic corrosion occurred. I know that this particular MBP was exposed to water. So I bought it very cheaply. I was able to clean and completely dry out the logic board and the MBP worked fine for a while but quickly the Q - W - E - R -T - Y - P keys got wonky then completely stopped working. I bought a replacement keyboard for cheap but then found out that it's held to the front frame with around 80 tiny screws. So I was using it with a BlueTooth keyboard. Recently I bit the bullet and for $69 bought an entire top case for my machine. Putting it in meant that the everything had to come out of and off the top case.

So you can see from the amount of corrosion, it doesn't take much to cause a failure. In this case a drop of liquid less than 0.5 mm would, over time with galvanic action, cause a failure. There was a post about someone who had their MBP in a leather case and when they opened it up there was a lot of moisture on it. It was winter where he lived and we figured it was condensation. So even without spills this could happen.

When I took this keyboard apart I was shocked to find how much crap was trapped under and inside the keyboard. Especially since I pride myself in never having any food/drink near my "precious!"

168 replies

Oct 8, 2016 2:39 AM in response to MattyRay

hi, I got the same problem! got a late-2011 Macbook Pro. Some letters have stopped functioning since 3 days ago! It started with D and now other letters !! the point is that sometimes works and sometimes doesn't work. The other point I'm going to add is that I'm typing this using the dictation option on Mac. Please help me if you know how to resolve this cause this is really really annoying.

Oct 11, 2016 2:19 AM in response to pjspjs

Now I am totally convinced it is OS related. Upgraded to Sierra, keyboard working slightly better. As Sierra was having Java JDK problems. I reinstalled the original mid-2011 OS Lion. Keyboard working perfectly and error free. Reinstalled a
vanilla version of Sierra. Seems to be ok with the keyboard key repeat slowed as per previous posts. I also realised that clicking on Safari links often went to rename option, and that seems to have gone away to.

Aug 6, 2018 11:26 PM in response to MattyRay

Have this issue too.


As the person above said, pressing option 5 times may work.


Another trick is to hold down the keys that are not working (all at once).


If those don't work, re-boot.... & use another keyboard 😉

Jan 15, 2017 3:51 PM in response to MattyRay

I have this issue too and sincerely hope someone can help me sort through what my next step might be.


Computer in question is my beloved MBP, mid-2012, running Sierra 10.12.2. (2.6GHz, Core i7, 8Gb Ram, etc.)


For past few months, occasional keys would not work—mostly the E, but others also on an apparently random basis. After doing cleaning and etc., I concluded (without checking this forum) that it must be a faulty keyboard. So I purchased a new keyboard and replaced without too much trouble. (As many have noted, a great many very tiny screws, but managed to not lose any and all seemed to go together OK.)


But, when rebooted, the problem is worse than ever. E.g., below.


The sentence is first typed (as is this post) with my Bluetooth keyboard normally reserved for my iPad:


This is a test to see what works on the keyboard. Not very much, as you can see.


Then I slowly typed the same sentence on the MBP keyboard with the following random results:


Hs astseat s aonbderu a ce

Tsa t rknt ear t eruchs y s

Iae satk thkbdoty hy yn s

Tsae ewtos t yoa ryuc can


Other observations:


Bluetooth keyboard works fine. No issues.


MBP keyboard—all keys work if pressed enough times. Sometimes work normally, sometimes have to keep pressing repeatedly—but always will end up with appropriate letter or symbol. With one exception. The 'Caps lock' will light up when pressed, but will not remain on.


Interesting observations:


When Keyboard window is selected from System Preferences, the bottom box option (4th down, reads “Use F1, F2, etc. keys…”) is flashing on and off. I have never seen this in any preference window.


Similarly, on the Keyboard preferences “Shortcuts” tab, the top option in the LH box (“Display) is appearing and disappearing, on and off.


I welcome thoughts and suggestions. Is it worth replacing the upper case?


I have no expertise, just being a fiddler. But it strikes me as odd that the Bluetooth keyboard works perfectly but the MBP does not. This would, all other things being equal, suggest a hardware issue to me. Might it be possible, e.g., that the MBP ribbon cable is not seated well? (I have checked and re-seated with no change in symptoms.) Is the top case somehow to blame? (I have no idea why this would be the case.) Are there software 'things' happening with the MBP keyboard that do not happen with the Bluetooth keyboard?


Thank you as always to the community!

Jan 17, 2017 1:24 PM in response to MattyRay

So after i tried all the fixes because the 5 times Option key worked only for 1 minute..So what i did in order to FIX my keyboard was that i recognise that when i was pressing keys on the right side of the keyboard for ex. Pressing all keys on the right side together .. and then trying to press my (not working keys or semi-functioning keys A,S,D) The keys worked for some time then again not.. so what i did was:

1)Power down the Mac

2)Clean the Mac Keyboard

3)Put cold air through the Keyboard

4)Start pressing all the keys on the right side and then with both my hands pressing all the keys together down with slide pressure just a bit -- Try different pressure times for ex. keep them all press for 10 sec then release.. after 5 minute that i was keep pressing the keys down..

5)Reboot my Mac and the A,S,D keys are now working like all the keys in my keyboard without any problem what so ever ...

P.s If that procedure did not work-then do the same but starting from (4) With your Mac booted to OS X u using..

Jan 18, 2017 8:45 AM in response to MattyRay

I also had this problem of keys working sporadically.


I'm using a macbook pro 15" mid 2012, french keyboard, and keys from e to o , and sometimes s to f were not working.

The only solution was to wait for them to be willing to work again, or to use a bluetooth keyboard.

The probleme seemed even worse sith temperature increasing.


Today I changed the keyboard with one found here : http://esimport.fr/

I'm so pleased to be able to write a few sentences without having to check for all my E, R, T, Y, U, I, O, P, S, D or F…


Keyboard sold 75€.

I guess it would have cost me 200€ in an apple store. Not talking about the fact that the computer would have been taken for a week or so…


I hope you guys can solve your problem like I did.

Regards,

dorian-v

Jan 19, 2017 8:20 PM in response to MattyRay

I was having problems with the keys between D and L. They'd work fine from a remote keyboard (usb) of course, but not on the Macbook Pro's keyboard. At first the problem was intermittent, but finally it got to the point that it seemed permanent.


OK, after ruling out the option key 5x solution, finding that mousekeys was not turned on, and trying miscellaneous and sundry other fixes found here and elsewhere, I figured out what part of the problem seems to be for me at least: bad fonts, and in some cases multiple copies of the same font


Started by disabling essentially everything but system fonts (and as I do a lot of design, there were a lot of fonts there, including some of dubious quality). Then noticed that for some reason FontBook was showing multiple copies of Times and Minion as being installed. Deleted the extra ones and now, for the time being at least, I am able to type as normal. So this may be something that you'll want to look into.

Feb 11, 2017 12:48 AM in response to MattyRay

For what it's worth, I had this issue too on a 2011 MacBook Air 13" for a couple of years. Very intermittent. I tried reinstalling the OS from scratch, disabling mouse keys etc. Nothing worked, and I couldn't work out if it was hardware or software.


I had my keyboard replaced by Apple 2-3 weeks ago and it's been fine since, so it must have been hardware-related. I hope this saves someone some time.

Feb 11, 2017 12:57 AM in response to dominic205

I agree, doesn't worth to waste time on this. I bought an external keyboard with a fraction of the 250euros they asked to replace it, but might not be feasible for everyone. I bought the new mbp in the meantime but the old one is still decent, except the graphics card which crashed twice so that's why i'm not sure worths to repair it. I hope this laptop is not a fail like 2011.

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Random Keys Working Sporadically

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