MattyRay

Q: 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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Q: Random Keys Working Sporadically

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  • by flixflux,

    flixflux flixflux Nov 6, 2014 9:10 AM in response to MrT2
    Level 1 (0 points)
    Nov 6, 2014 9:10 AM in response to MrT2

    Same issue here, late 2011 MBP running 10.8.5. This also happens right after startup when trying to log in with my user, therefore I don't expect it to be a third party issue - unless it's caused by some background service that's loaded before logging in. On my machine this issue appears randomly but also usually disappears again within one or two minutes. Letters are typically those in the top row, and mostly vowels I think (U, O, I). This appears like one of those issues that can be really hard to reproduce and fix for a company, but with Apple charging the hardware prices they do, I would expect an official solution here, even if it's nothing else than hitting option 5 times in a row. Because this bug, while it appears, renders your machine completely useless.

  • by finin,

    finin finin Nov 17, 2014 8:05 PM in response to MattyRay
    Level 1 (0 points)
    Nov 17, 2014 8:05 PM in response to MattyRay

    Me too.   Bought MBP in January 2012.   It just started giving me intermittent keyboard problems.  keys in middle row often do not work.

  • by Vinny In Vancouver,

    Vinny In Vancouver Vinny In Vancouver Nov 19, 2014 8:03 PM in response to finin
    Level 1 (0 points)
    Nov 19, 2014 8:03 PM in response to finin

    Same issue here with my 2010 MBP. Never dropped it or spilled any liquid on it. At first, it was just the 'S' key. Then, it spread to the 'F' key. I removed the keys and cleaned them - had a bit of dust but nothing major. Didn't fix the problem. Now, it has spread to the 'C' and 'V' keys. Have resorted to using an external wireless keyboard plunked on top of the MBP keyboard (works). Phoned a local Apple repair shop, and they claim that my keyboard will need to be replaced. May consider going through with it to save money on a new one. Sigh.

  • by BlindO_ptimism,

    BlindO_ptimism BlindO_ptimism Dec 1, 2014 7:37 AM in response to Vinny In Vancouver
    Level 1 (0 points)
    Dec 1, 2014 7:37 AM in response to Vinny In Vancouver

    Just wanted to add my voice to this topic.  Macbook Pro 2012.  Keys E, R, T, Y, U, I and O stop working intermittently.  Always happens in unison.  No droppage. No spillage.  Typing this via keyboard viewer.  Started yesterday, so no conclusive results yet.

     

    I'm a mug.  Owned Apple products since 2008 and the hardware always fails.  Constant problems.

  • by iCulture,

    iCulture iCulture Dec 1, 2014 11:13 AM in response to MattyRay
    Level 1 (0 points)
    Dec 1, 2014 11:13 AM in response to MattyRay

    This problem went away for me. In part I think because the weather got cooler, and I think heat may have played a role, but more importantly because I prised off the offending keys and vacuumed out all the crud that was under them (also had to use a tweezers to pull out hairs that had snuck in there). Prior to that I had a different solution – to carry around a separate Mac bluetooth keyboard I happened to have bought for a different purpose; worked fine, bit of a hassle, but much cheaper than repair alternatives.

  • by ibookiepr,

    ibookiepr ibookiepr Dec 2, 2014 7:37 PM in response to iCulture
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    Dec 2, 2014 7:37 PM in response to iCulture

    Same deal here. 2012 MBP. O, u, i, t, y keys stop responding or respond intermittently.

     

    Had issues with this earlier in the year, and then it stopped. Paired a bluetooth keyboard to fix the problem. Man, this is annoying, as I depend on this machine for work.

     

    I really don't want to purchase another yet. And I imagine it will be prohibitively expensive to fix.

  • by finin,

    finin finin Dec 2, 2014 8:56 PM in response to finin
    Level 1 (0 points)
    Dec 2, 2014 8:56 PM in response to finin

    I took my laptop (Purchased in January 2013, a it turned out) to the genius bar and they said the fix was to replace the topcase, which includes the keyboard and battery.  I had Apple do this ($438 with labor) and all is fine.

  • by spudnuty,

    spudnuty spudnuty Dec 3, 2014 12:12 PM in response to MattyRay
    Level 5 (7,097 points)
    Mac OS X
    Dec 3, 2014 12:12 PM in response to MattyRay

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

    Front and Back Array.jpg

    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.

    Contact pads .jpg

    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.

    corrosion membrane.jpg

    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!"

  • by bronius,

    bronius bronius Jan 21, 2015 7:45 AM in response to spudnuty
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    Jan 21, 2015 7:45 AM in response to spudnuty

    Same issue ere as escribe.  It's te mie row eys tat are not:

    as;'

     

    Comes and goes. Only thing I can add is that holding down the key (prolonged, not heavily) lets it eventually press.  And then it will continue to respond for a while.  It's like something confusing the kb scan.

     

    THANK YOU for the fantastic close up shots posted here of the mbp kb guts!  And as you can see by my typing here, the "issue has gone away..." for the time being..

     

    Best - hth

    -Bronius

  • by spudnuty,

    spudnuty spudnuty Jan 21, 2015 12:36 PM in response to bronius
    Level 5 (7,097 points)
    Mac OS X
    Jan 21, 2015 12:36 PM in response to bronius

    Bronius,

    Try plugging in a USB keyboard and report back the result.

  • by bronius,

    bronius bronius Jan 21, 2015 2:13 PM in response to spudnuty
    Level 1 (0 points)
    Jan 21, 2015 2:13 PM in response to spudnuty

    Thanks for your reply!  I tried:

    • Without USB keyboard, the issue comes and goes on the mbp
    • While it was occurring, I plugged in the USB kb, problem persisted on mbp but USB keys fired perfectly
    • Left USB kb plugged in and worked on other things until the issue arose again; same results as before: mbp kb "D" key and neighbors lapsing, USB keys worked just fine

     

    To better explain, here's more: While "it's happening," I am able to hold down the "D" key.  Normally I would expect 1 D, a delay, and then a stream of Ds nonstop. Instead what I get is a long delay before the first "d" followed by a brief delay and then another "d" and then maybe a short burst of 3-6 Ds and pause and then another 1 and then delay, etc...  However, if I get it to give a good burst, it may hiccup a bit before then consistently working again! There does not appear to be a pattern to it, and I strive to maintain constant pressure (not flexing or rocking the key or its neighbors).  It's always only D-L from what I observe.

     

    Apps I suspect might be messing with me:

    • Tuck (really awesome, simple window manager by IrradiatedSoftware)
    • Time Machine backup (it just ***** the life out of everything, doesn't it?)
    • Chrome browser (Sometimes the issue appears to coincide with opening of a new browser ..)
    • The Great Suspender (Chrome browser plugin which parks a tab to conserve resources)

    ...but I suspect it's not any one app but maybe some common thread messing with an OS level kb input scan or like Great Suspender freezing an operation at an inopportune moment.

     

    Note: Nothing unusual in Activity Monitor like high CPU or something..  I believe a system restart clears the issue but it can return very quickly.  I do restart with "restore windows," and my Chrome is usually 4 concurrent Chrome profiles and 12-25 tabs total across all.

  • by spudnuty,

    spudnuty spudnuty Jan 21, 2015 3:28 PM in response to bronius
    Level 5 (7,097 points)
    Mac OS X
    Jan 21, 2015 3:28 PM in response to bronius

    "mbp kb "D" key and neighbors lapsing, USB keys worked just fine"

    So it's clear to me that it's not a software issue:

    "mbp kb "D" key and neighbors lapsing, USB keys worked just fine"

    To explain the matrix design I recently replaced the top case in my 2011 13" MBP. I was interested in why the "Q - through - -P"  keys all failed.

    So I disassembled it.

    contactor array .jpg

    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.

    Front Keyboard Membrane.jpg

    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.

    corrosion membrane.jpg

    So here you see a site where galvanic corrosion occurred.

    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.

    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!"

    So in your case my theory would be that something got into the membrane between the front and rear. It's resistive but causing sporadic problems that are probably unrelated to what you're doing.

  • by bronius,

    bronius bronius Jan 22, 2015 6:40 AM in response to spudnuty
    Level 1 (0 points)
    Jan 22, 2015 6:40 AM in response to spudnuty

    Thanks or reposting an reiterating.  I'll give this USB a try (so hard to use the remapped keys and no trackpad!) while i work in a time to get my mbp into service.  I take it that once disassembled, the membranes and loose parts can be a challenge to reconstruct, and it's not likely possible that any corroded connective wiring can be repaired.

  • by spudnuty,

    spudnuty spudnuty Jan 22, 2015 8:18 AM in response to bronius
    Level 5 (7,097 points)
    Mac OS X
    Jan 22, 2015 8:18 AM in response to bronius

    " remapped keys and no trackpad!)"

    Yup easier with a Mac keyboard and a mouse.

  • by bronius,

    bronius bronius Jan 22, 2015 8:59 AM in response to bronius
    Level 1 (0 points)
    Jan 22, 2015 8:59 AM in response to bronius

    [edit] On your strong inclination that it's corrosion, short, or breakage, I am typing now on the mbp and wiggling the film between the problematic keys with a credit card in hopes of jostling the connection, and I believe it might be making a difference but can't be sure.  There just aren't consistent observations: I've even visited this same thread three times in the past 6mo as it "seems to come and go in waves."  My local mac store always says 3-5 days wait -- ain't nobody got time for that!. [/edit]

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