Random Keys Working Sporadically

Thanks, Spudnuty! You've given me the motivation I nee to take out my keyboard and look at it. In my case, I have a suspicion that I may find cat fur lodged in there somewhere...

I solved it today after months just by changing time response at keyboard settings.

Sistem Preferences....Keyboard....Key repeat (move slover)

All the best,

Sabina

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!

It worked! Thanks.

Excellent

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!

I have this problem for months now. Your solution worked for me right now and it's pretty impressive, because I had many keys not functioning just before doing your procedure. Just after adding a new keyboard, all keys are back! I don't know it will always solve it in the future, but thank you for sharing it. 🙂

Thanks that worked.. partially as diminished the problem.

My issue is mostly Q to P line.

I am convinced that it was El Capitan making the keyboard more sensitive, or a related firmware upgrade. My son changed the keyboard to English, and it got worse. I changed it back to Swiss French and it got better. If I flex the keyboard downwards the problem disappears for a few days, (Putting downward pressure on the middle of the keyboard).

Regards, Phil

I think it's just a hardware problem.

I have the same issue in my 2011 macbook air with the q-to-o keys.

The only long-term solution seems to be the replacement of the keyboard, but it's quite hard for me and I don't want to spend a lot of money for Apple's assistance.

It's a pity since otherwise the laptop still works great..

Here's a picture of the front membrane contacts on a MBP that I posted earlier in this thread.

So as you can see the contacts here are all arranged and wired horizontally. Any crack in the trace will cause the downstream keys to stop working. (Not sure which way is downstream.)

Sometimes flexing the keyboard will cause it to start working again but a permanent fix involves replacing the keyboard. It's quite a pain to do the replacement due to the number of screws and the fact that everything has to come out of the MBP but the replacement keyboards are cheap now.

I understand the hardware issue. However, my problem started with an update to El Capitan and related firmware fixes. I think previously the detection of the hardware (key functionality), by the software (OS) and related microcode was more fault tolerant. Since I reduced the key repeat speed. It has mostly stabilised. I am not saying it has gone away. I can live with it without having to change keyboards. For me the problem is a combination of poor keyboard design and poor software fault tolerance. Previous OS's were more tolerant as nothing else changed :-)

Right on! That's why I'm still using Mavericks 10.9.5 and continue to do so on all my new installs. It seems unintuitive to me that an OS update would cause only a certain keyboard string to fail but I've seen weirder anomalies!

That is really strange because I had the same problem with my u, i and o. I tried the Option 5 times solution and all the other solutions on the Apple recommended pages and they didn't work. Then, I tried your method - Ctrl 5 times - and it worked. W T F indeed!

Same problem:

t y u i o sometimes does not work.

It seems that they work better when my macbook pro late 2011 is hot!

Sometimes by pressing all of them at same time couple of times, it starts to work again....

I suspect that this as something to do when they have changed my motherboard with newer version, but the said that is has nothing to do with that 😟

Only was to solve this irritating problem is changed the whole upper case! 317€ (218,12€ upper case + installation)

With external keyboard all is OK....

I guess I'll just live with it for now.

Called apple Today. FINALLY THIS WORKED!!!!! I tried everything else and nothing else lasted for more than a couple minutes.

How to Reset NVRAM on your Mac - Apple Support