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

Feb 18, 2016 3:50 PM in response to fredfromal

Sorry to see that this problem is continuing for you.

"I can't get anything done without plugging in an external keyboard. That's shown some issues too. "

So that's problematic in that it points to another problem that's not hardware related.

It might help to know the exact model, year and OS you're running.

"I've decided to get the "top case replacement" done"

Not so sure I'd do that before exhausting all other possibilities. How long ago did this problem appear?

Feb 18, 2016 4:47 PM in response to fredfromal

Re top case replacement..


Be prepared to wait.


When I dropped off my computer on the 7th, I was told there was a new top case in stock and the wait would be 3 to 5 days. After 5 days with no word I got online to check the repair status. Progressing or something like that. Not too long after I checked I got a phone call from the Apple Store lettinig me know the in stock top case was defective, incorrectly machined or something to that effect, and did not fit. Another one was ordered.


I just checked today and the repair is still progressing...


Tokay makes it 11 days since I dropped the unit off. I'm a bit disppointed at the time this is taking.

Feb 20, 2016 11:15 AM in response to spudnuty

The issues started showing up about 18 months ago (give or take). At first it was a rare and transitional issue, then got progressively worse over time. I can't pinpoint the "start" date for sure, but after reading all of the posts correlating OS updates to the issues, it remains plausible. Per another of my posts after installing the most recent OS update, the keyboard tanked. T,Y,U,I and O (Try typing any sentence that does not use those letters and you'll quickly understand what level of frustration I faced).


One of the software related things that recently caught my attention was a discussion regarding potential cycling of the processors to keep temps down and fan noise to a minimum, that has now supposedly been integrated within the OS and regulated by the computer "profile" commands. T or F, I have no real evidence. I believe the newest processors do incorporate a Boost Cycle (2.7GHz dual-core Intel Core i5 processor w/Turbo Boost up to 3.1GHz). Just another plausible hunch.


Wonder if IAmNotaMachince can advise on the Apple quoted cost to replace the upper case, regardless of the wait time.

Feb 21, 2016 1:32 PM in response to Lini_Ice

Like many here, I too had an issue with letters Q through O - but not P - which indicates that somehow those letters are linked in circuitry or whatever. After months of reading forums like this one, and using Apple support over the phone, which had me reset my System Management Controller, which I'm pretty sure has nothing to do with the keyboard, I visited my local Genius Bar. The first "genius" insisted that if I just sort of massaged the keys in question around the edges, they would probably work. Then he recommended replacing the hard top. No attempt to actually research or diagnose the issue. I spoke to a manager on the phone a few days later and he had me bring my MacBook back for a more thorough examination - and then simply had the techs replace my hard top. Cost: $130, though he eventually dropped the labor charge. What really got me was that there was no acknowledgement that this is a known issue; there must be a reason why this happens. No attempt to diagnose. "We don't do that here," I was told. "We just replace parts." It would be like an auto mechanic not simply changing the oil but just replacing the whole engine - and without diagnosing that maybe there's a leak somewhere. I just don't ge it.

Feb 21, 2016 3:16 PM in response to fredfromal

The machine is fixed! I received a phone call shortly before 1pm telling me the machine is ready to pick up. I won't say I was not excited but I took the fastest of my two cars and the one with the radar detector to drive the ~10 miles to the Apple Store.


Pick up went pretty smoothly although there was a bit of a difficulty regarding the repair charge.


The repair charge was more than I was told. Seems in addition to the top case a "bracket" was found in need of replacement. I have no idea what this bracket looks like, why it required replacement. I balked as I had paperwork showing the cost to be $174.23 not including taxes.


The Apple employee excused himself and left only to return a minute or two later and said he could accept the initial charge amount, plus taxes. So I paid him.


Please understand I would paid the extra amount for the bracket. I was just caught a bit off guard since it had not been communicated to me something over and above what I was told was wrong was found wrong. I mean if the bracket is broken, or worn out, or whatever and needs to be replaced it needs to be replaced. Another $10.23 is not the end of the world.


Oh well. The Apple employee was cool, handled it calmly, very professionally. (And I was calm and cool, too.)


Here's what I was told the breakdown on the repair would have been without the bracket:


661-6595 Topcase W/Keybard, No Trackpoint, 13" MBP: $135.23

S1490LL/A Hardware Repair Labor: $39.00

Total: (Tax Not Included): $174.23.


Here is the breakdown on the repair with the bracket:

661-6595 Topcase, W/Keyaord, No Trackpoint, 13" MBP: $135.23

923-0156 Center Bracket: $10.23

S1490LL/A Hardware Repair Labor: $39.00

Total (Tax Not Included): $184.46


I just looked at the credit card slip and the $10.23 charge for the bracket was removed and tax was $12.86 (9.5% Good old Jerry Brown the governor needs the money to build his legacy "high speed" railroad. This is CA so the only thing "high" about this railboard project is going to be its cost and cost overruns!)


Where was I? Oh, yeah: Total: $187.19.


So there you go: My MBP is back and I'm using it now. Recharging the battery, it was down to 15%. I'm going to really work the unit hard to get it warm to make sure the key problem is gone.

Feb 21, 2016 3:26 PM in response to IAmNotAMachine

Good for you. Funny thing about the cost. In my previous post I mentioned that they tried to charge me $130 before lopping off the labor charge. What really happened is that they quoted me $80 for the whole thing on my first visit. Upon my return, and after citing that figure to the manager without trouble on the phone, they tried to charge me $130. I said I was quoted $80 and the guy says, "We don't do anything here for $80." Fortunately, the manager was right there and took care of it, but weird. Recommendation: Always challenge the cost, because it seems they are quite, um, flexible.

Mar 12, 2016 5:20 AM in response to MattyRay

Hi!

I have a MacBook Pro 15" from 2011. It has the problem of intermittent key not working. In my case it is the keys t-y-u-i-o.

I have succeeded solving the problems some times by simply pressing a number of the problematic keys down at the same time! Suddenly they startet working again.

I don't think the problem on my keyboard is a physical one. I think it is a kind of software bug.

Mar 29, 2016 11:32 AM in response to IAmNotAMachine

My R-T-Y-U-I-O keys were not working either. I did hold them all down at the same time and they began working again. I have just done this so I can't say if the fix will last. Any conclusions yet on Hardware or Software issue? At the top of this post it says "Branched to a New Discussion" but when I tried to access the New Discussion I was Denied. (I have MBP 15" Late 2011.)

Mar 29, 2016 11:43 AM in response to Amy Jenkins

Well, in my post of Feb. 21, I reported a new top case and a "bracket" solved my 13" MCB (built mid-2012) not working keys behavior. For my machine then it was a hardware problem.


All I can advise you do is try the software solutions, check the settings, and if this proves to be a permanent solution for you that is just great.


For me it proved to not be a permanent solution and I went ahead with the Apple tech's suggestion to replace the upper case. (The fact a bracket was also needed was not known at the time.)

Mar 30, 2016 1:38 AM in response to mathiascraig

Same issue with my 2011 air, which i love and will never replace if i can. 2,W,S will stop working every so often. Was able to fix it by half pulling off some of the keys and working them around a bit. They worked after. Everytime they stop working I just pull them up a little then they start working again. This is the only solution I've found after trying all other solutions.

May 25, 2016 12:00 AM in response to SorensenDK

My y u i o keys were not working. This has been happening on my MacBook Pro laptop (13 inch, late 2011) for about 6 months now. I have discussed this on the Apple Help Chat Line. While recognizing that it is a random problem, which to me seems to rule out a hardware problem, their only solution is to take it in to an Apple Store for repairs. I had previously done their suggested fix of re-installing OS X El Capitan Version 10.11.5. That fix worked for almost 24 hours. Another fix I have been using is to have multiple Input Sources for the keyboard - I use Australian, British, Canadian English and US, and alternate among them. This is a temporary fix. I have managed to type this paragraph by holding down the y, u, i, o keys at the same time when they randomly stop working, as they have frequently done as I type this. Thank you for this suggestion which seems to be working very well, and I plan to use until Apple fixes the problem permanently.

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Random Keys Working Sporadically

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