Random Keys Working Sporadically

I think you're on to something here, but changing my search engine had no effect. I believe it's background operations.

Unless there is permanent failure due to a mechanical issue, these conditions seem to be software/firmware/operations related.

My "floating key blackouts" can be traced primarily (lost them again, took 7 key presses to get back) to browser use. I'm still working on isolating the root cause(s), but I have had some pretty good success by reducing as many "influencer's" as possible. I've taken the following steps:

• Look for and remove as many preferences left behind by old, deleted, or outdated programs. As an example, I had a startup item left from Virtual Machine and there were dozens of pref's left from trial programs.
• Turn off as many system preference "extras" as possible. These were mostly in the accessibility, trackpad, keyboard and mouse sections, but I turned off as many "options" as possible.
• Re-installed OSX

At the moment, I continue to lose the T,Y,U,I and O keys repeatedly, but for shorter periods of time than before. Quitting the browser has helped, as has repeated pressing one of the disabled keys (vs. holding down) until it begins working again. It's taken any where from a few key presses to over 20, but rarely fails (lost the i for a moment, took 12 key presses to get it back) When I do that they all work for extended periods of time.

Things that had no effect:

• Restarting
• Reset PRAM
• Reset PMU
• Running Disk Utility
• Running Disk Utility from OS Recovery
• Changing keyboard (US to British, deleting US, restart, re-enable US. Did have some success at first but never lasted)
• Banging head against wall

OnyX app results have been significant. There are features to reset all types of background caches and processes and reset file associations (i.e. override ïnfo"settings to associate a file with a certain program).

My gut tells me the issue is rooted in background ops (caching, kernels, etc.). Taking a SWAG at it, I'd say related to spotlight indexing and the feature which automatically saves versions of documents. I'm experiencing numerous "key dropouts" while writing this and it incorporates auto-saves. I'm going to look back through the posts to see if I can determine a match between the rise of issues and new OSX versions/features. If I recall correctly, at some point these background operations were "reclassified" from being done during times of idle (sleep) to "always on". As this lost key issue seems to be restricted to pre 2013 MBP's and the 2011 and 2012's highly susceptible, it may be related to some type of hierarchical sequencing that only affects older models. Is it/ it is possible newer multi-core processors might reserve a core to process these background operations without affecting operations in the forefront. Again, I must note it's a SWAG, but as it keeps occurring and disappearing it's probable.

If I find more, I'll add more, but I hope Apple can find some way to address.

Try this, i think it will fix it 🙂

And here’s the fix that worked for me:

1. Go to System Preferences (you can get there from Mission Control, or the top left Apple icon on your screen, and then click System Preferences.
2. Go to Keyboard.
3. Go to the Input Sources tab.
4. Click the + button (bottom left of window).
5. Add a new keyboard (preferably of a similar language). We had British running originally, so we added U.S. below it (i.e. you should now have 2 keyboards in the list).
6. Your “broken” keys should now be working again (try with glee in an open text edit window, or similar).
7. Feel free to remove your newly added keyboard (i.e. you should just be left with your original keyboard), as the fix should still work. You can do this by selecting the newly added keyboard and clicking the – button to remove.

Hi everyone, here's an overview of a lot of the ideas and solutions, and what may be the root cause of the problem.

Problem

Some keys on the Macbook's keyboard do not work. Specifics:

• It's intermittent (they sometimes do work)
• it's a row or a cluster of keys (they're all next to each other)
• It doesn't affect all of these keys equally (one might work while others don't)
• It can also involve keystrokes being delayed, i.e. you type "e" then "r" but it comes out as "re"

First aid

• There's a list in an Apple Help page which helps in situations where settings (mostly accessibility settings: keys doubling as mouse controls) are the cause.
• EASY TO TRY: Other users have suggested and had success with tapping the option key five times. That is a way of switching between accessibility modes, which affects the keyboard.
• EASY TO TRY: adding a new input source (e.g. a British English keyboard) via settings. This appears to reset the keyboard's connection with each of its keys, which may help.
• MEDIUM EASY: Download TinkerTool (an app that basically gives you extra System Settings to tinker with), go to the General tab > Keyboard. There are two options: whatever is currently selected, try the other ("Support key repeat" or "Hold key to select diacritic character")

However, these are not likely causes/solutions if only a bunch of keys (often the row between E and O) is affected.

Causes

• If it's only a few keys affected, the cause is likely to be a combination of hardware issues (i.e. there's really something wrong with the keyboard)
• Software may play a part too: certain settings or OSX updates may make the computer more sensitive to physical problems with the keyboard. But doing something about the software will never solve your problem fully.
• The hardware problem seems to be that the electric signals do not run correctly in this group of keys. This is usually caused by tiny specs of rust, moisture, hairs; by ruptures in the circuit; or by other ways in which the whole process (where tapping a key gets turned into an electrical signal) can go awry
• Since they're grouped, a problem in one key may affect the others. In the E-O group, often the E and maybe the R will work, while keys farther to the right won't.

Stopgap solutions

On the hardware side, these solutions may help, but likely not for long or not for all keys.

• tapping all the affected letters at once (this triggers a stronger electrical current, which can shock the keys out of their deafness). This is very likely to help you in the short term while you go Googling for answers
• pressing hard on the aluminium casing nearby the keys. The layer below the keys which receives the electrical currents may have gotten too far away from the keys and the casing.

Root causes:

• It's your physical keyboard where the problems lie. Have you been placing it on your lap, holding it in strange non-horizontal positions, and has the laptop been hot while you were doing this? All of those things may eventually cause your laptop to slightly deform below the surface.
• Have you been using diacritical sign often (é, ü etc)? And have you been doing this by long-pressing your keys? I have, and it just so happen that most of the keys I long-press (the vowels) are in the e-o section. I may have been pressing too hard, thus increasing the distance between the keys and the layer below them.

Real solutions:

• Cleaning below each key. If your E key works while those to its right don't, clean below the E and the R keys.
• In the same spirit: vacuum your keyboard, and/or hold it upside down and gently shake or tap the laptop against a tabletop. In other words: clean out the junk.
• Bend your outer case in such a way that the middle of the keyboard (the keys and the aluminum around them) will budge just a little bit closer to the core of the machine. Be careful with this! It's both the best solution and the most dangerous one for the life of your laptop.
• Replace your keyboard (the plastic stuff below the aluminum casing)

Good luck!

This is a great write-up! Thanks!

I ended up replacing my keyboard.

In case it helps anyone else, here's what worked/didn't work in my situation, when my a, s & d keys stopped working. For all of the hardware stuff, I used the ifixit guides, which are excellent. I didn't have the right tools, so I bought the Stronger-brand TK-LA40 toolkit from Amazon because it was cheap (about $15) and it ended up working surprisingly well. I've heard the ifixit tools are excellent, as well. If you use the TK-LA40, I'd suggest also getting one or two pencil-like spudgers, because the ones that come with the kit are shaped like guitar picks, and they aren't useful in this particular situation.

For anyone who has no experience with computer hardware but wants to try this on their own: I have a few bits of advice that aren't mentioned in the ifixt manuals (which are otherwise excellent):

1. You should either wear a grounding (anti-static) strap or make sure you touch the metal computer case before touching the logic board (static discharge can blow out the sensitive circuits on the board) AND, as much as possible, avoid touching any metal parts on the logic board.
2. There are A LOT of different types and sizes of screws in the macbook. Even some that you would assume will be the same (e.g., the 3 screws holding the fan to the logic board) will be different from each other. DON'T TRUST YOUR MEMORY. What I like to do is draw a rough outline sketch of the part I'm working on and then tape each screw to the right place on the drawing as I remove it. Not only does that ensure I know what goes where, it keeps the screws from getting lost and saves time later, when I just grab the screw off the drawing instead of sorting through a pile of them to find the right one.
3. Keep a magnifying glass handy.

So here's what I did BEFORE replacing the keyboard, to verify I really had to:

1. Rest SMC and PRAM: didn't help.
2. Took off all key caps and meticulously removed all dust, crumbs and cat fur. That made no difference.
3. Attached a bluetooth keyboard; a, s & d worked fine with that, confirming my suspicion that problem was hardware, not software/settings.
4. In System Preferences, changed the modifier key layout to use caps lock as a command key, since the similar key on the cheapy keyboard wouldn't work for that.
5. Downloaded Karibiner (free keyboard remapping app) so I could disable the built-in keyboard and set the bluetooth on top of it. I have a cheapy keyboard originally intended for use with and Android tablet, and it is almost exactly the same size as the built-in keyboard so it fits there perfectly while the laptop is open. I used this until I was able to fix the built-in keyboard.

So none of that worked. Now, here's my experience with the new keyboard project:

1. Ordered a new keyboard on ebay. About $40, including shipping. This was a major exercise in frustration because of the horrible little screws on the keyboard (50-60, depending on macbook model). Having spent a good portion of my career working on computer hardware, I wasn't worried by the horror stories I read online about people not being able to get these screws loose; I figured it was probably due to their relative inexperience working on computer hardware, since many people had no problem. I am now humbled. Even though I had the proper screwdriver, between the really tiny size of the screws, the Locktite that has the screws virtually glued in place, and my old eyes, I could only get about half of them out. The rest stripped, and I couldn't see them well enough to tell they were stripping until it was too late. As far as I can tell, it's luck of the draw whether it will be easier/harder to remove the keyboard from a particular laptop. After trying various methods of getting the screws loose, I gave up and moved on.
2. Bought a refurbished top case on ebay (about $65 including keyboard and shipping). Relatively smooth sailing after that, with only one small hitch:
3. Fired up the laptop and found that both Shift keys, the Control key, all Function keys and the left Command and Option keys did not work. Since the keyboard cable is easily accessible once the bottom plate is removed, it was really easy to re-seat the cable; that did the trick. The laptop is now working great! Whew!

Thank you very much! That worked for me.

It took me:

• one call to service,
• taking of the keys that not working from keyboard,
• google the issue once…

Stil, shame on OSX UX designers. This acessibility feature is so dumb and random. 😠

"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.

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.

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.

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.

Just confirming that 20 minutes ago my keyboard was doing the same thing, even the same keys, which makes me suspicious. I have a Spring 2011 macbook pro. All is well now, but I will keep an eye on it.

@MattyRay, please post back if you find a fix.

I have the exact same issues for my Late MBP 2011. This was the first post that had the same keys in question not working (t, y, u, i, o).

I tried cleaning under the keys but that really didn't help. I also tried the things in their support article, but they didn't work either.

I'm still looking for a solution, but when it stops working, sometimes it helps to press down hard on the area where the t, y, u, i, o letters are. Maybe that is just psychological, though. I don't think I had any issues with a USB/bluetooth keyboard, so you can use that too. It is just odd that it *sometimes* works and *sometimes* doesn't. It makes one assume that something is loose or not reacting properly...

It happened to me sporadically for 2 days, and since it has been fine. I did try to wipe down my keybard and blow air around those keys. But I never found a solid answer as to what the cause and real solution were.

Hope you get lucky!

Omg, adding that I'm having the exact same experience: Spring 2011 MacBook Pro, and my t, y, u, i, and o keys work only sporadically.

We fixed the issue for a while (messed with the ram, repaired disk permissions, cleaned out a ton of things in the hard drive library per some online suggestions), but it's back again after 3 weeks of keyboard bliss. I'm using an external bluetooth keyboard to type this.

The problem's recurred for the last 8ish weeks -- enough time for me to notice that this seems to happen during the same periods when my laptop starts to easily overheat. Like, my laptop seems to have "seasons" during which I suddenly have to prop books beneath it (when working in certain scenarios) in order to keep the fan from running high.

Not sure if it's coincidence that the keys get intermittent during these times, but it's def curious. ?

If anyone finds a solution, please let us know!

Early Spring 17" Macbook pro and having the same issue. 2 days ago y,o,h,l,n,0,., and arrow keys stopped working. For a moment 'control' locked on but that faded away after an hour or two.

- Pressing keys 5 times ( opt, alt,cmnd,shft) does nothing.

- I have checked all preferences (speech, dictation, universal, keyboard, text) as mentioned in blogs.

- I have also created a new user to varify there is no issue with specific account preferences.

- I reset RAM ( press & hold Command-Option-P-R keys before the gray screen appears on restart )

Keyboard viewer shows nothing when pressing these keys however when keys are clicked through keyboard viewer they works fine.

I noticed this began after I wiped off my keyboard while the computer was on (on the log-in screen) which is why I thought that this could simply be some bizarre setting I mistakenly turned on while pushing multiple keys that renders keys non functional but after reading 8 hours worth of online tech support, blogs, etc., nothing suggested works. I am careful with my Mac and have gently cleaned it the same way I have been since 2011. This is the first keyboard issue. There seems to be a lot of people with this same problem, I hope there is a fix I am overlooking. I am going to the Mac Store today and will update with issues.

I've heard Macs are 4 year machines before the built in obselete features kick in. I definitely love this 17" so I hope this is just of single, correctable glitch.

and sidenote, if the new iphone is not waterproof I may just be convinced Apple has lost its competitive edge. 😟

I have a MacBook Pro purchased in 2010. Letters A through L on my built-in keyboard (the entire middle row of letter keys) have stopped working. At first it was sporadic but now they seem to be out for good. This problem just developed over the past few days. I've tried all the troubleshooting suggested. Nothing works. I'm typing with an external bluetooth keyboard now. From what I've read, it could be that the battery has warped and is affecting these keys? Hesitant to buy a replacement battery given the machine is already four years old and may just continue to deteriorate...

Exact same problem here. With me, it's the middle row from A to L. If I press down hard and repeatedly they work. Then they don't. Then they do again. I'm struggling to type this out now.

Early 2011 15" Macbook Pro. Odd that all these similar machines should suddenly have this issue.

I have a Macbook Pro 15" early 2011. At first, the E would give me trouble/would sometimes (not) register. Just a couple of days ago other keys (r, t, y, u, i, o) sometimes have problems registering. Pressing harder is not a solution. Keep pressing them often does work, sometimes within 5 seconds, sometimes up to 10 seconds, sometimes not at all. And a random period later (often a couple of minutes) the non-responsive keys work (for a while) again...

I have done SMC and PRAM resets. Taken off the back-cover and removing and re-inserting the keyboard flat cable. None of the action solves the problem.

This machine has already given me more problems ("monday model"?). Several keys have worn off (like: you can't make out whether it is an a, d etc). I had it looked at by Geniuses and resellers. Best i get is "we have never seen this before" and one time "maybe it's something in your sweat". Not: "We are an A-brand, this is not supposed to happen, you paid a premium price for this product, we will replace it free".

I had the misfortune of having it make a nasty fall once: that will ensure that every malfunction will be tight to that fall :-(. A couple of months after the incident a yellowish discoloration started to appear in the left lower side of the screen. Found others on the Net with similar problems. The display was replaced (although they said it might be related to the fall and i really needed to talk a lot to reason it was months after the fall this started and i read about similar problems).

A year later, after returning from holiday, i opened up my Macbook: battery had died, had to buy a new battery and was told it was a known (?) problem that when you totally drain the battery, it may die (really? 2011 A brand tech?). Only a couple of months later the screen stopped making any sense (unreadable, also at boot): brought it to a service store, and i had to pay for a mother board replacement. And now the keyboard :-( ...

Same problem for me! (macbook air 13" 2011) q till o are not working very well. The problem started just with the letter w but soon it began to spread out on the other keys. After several software attempts (fresh insall of mac os; Pram; SMC) I opened the macbook to see if there is any dirt inside. I cleand the whole keyboard (which was very hard to reach) with alcohol and reassembled it, but unfortunalty it still has the same problem. Some times the keys work and sometimes they dont.

Has anybody brouht it to the genius bar? What did they say about it?

Actually, I am a bit disappointed right now. I would not have expect such a problem after 3 years. I also have a lenovo think pad which is 5 years old which has no problem at all (except of the battery).