t-y-u-i-o keys intermittently work SOLVED (SO FAR)
UPDATE 03-10-17 : You don't have to read the saga below if you don't want to. As was suggested to me several times by the helpful people on this site, it IS a hardware issue. Don't waste any more time and get the top case replaced. I waited until I could better afford doing so (I paid $371.00) at a local Chicagoland family owned store that's been around since the 1930's (I think) which happens to be where I purchased my macbook pro in the first place. As soon as I experienced that heat surge I should have called Abt immediately instead of blowing it off and writing it off as just an issue with having a bottom protector cover on it. I took that bottom cover off thinking it would help and did nothing because the keyboard didn't act up until a few months later. The fact that I smoke and have a cat doesn't help either of course. I was told that the cover might have had something to do with it and a heat surge like I felt can be enough to screw things up. I am still wondering whether or not a software I had at the time had anything to do with it. Two apps I've questioned were smcfan control and/or F.lux. I only mention this because about the time I had those on my machine, we would find my macbook still lit up in the morning...Usually when I fall asleep to a podcast, the screen would go dark sometime during the night but for some reason, after installing one or both of those or maybe even having some sort of update, my husband would often say he keeps seeing my screen bright and on with me asleep where he didn't used to see that before. I was slow to look into that problem too. What a big bunch of expensive lessons I have learned about my procrastination and habits! Good luck to everyone and thank you so much for this website and all you helpful people. Hope something in my posts helps SOMEBODY. end of 3/10/17 update.
Holding all the keys down at once for a while seems to get them functioning properly. I've reset the PRAM and the SMC. After my most recent reset of the SMC, the fan came on LOUD and battery was not recognized.
Apple online help insists it is a hardware issue but hardware testing reveals no issues. tried cleaning carefully to no avail.
I've reinstalled he O/S under the guidance of an apple tech and had a brand new external hard drive backing up all my crap. I told the technician I was worried that El Capitan may have caused the issue and I thought perhaps a reinstall would get me back to mavericks but it didn't. I still have el capitan. So. Other than holding down all the keys or sometimes just one of the keys for a long time, nothing else really works. All those quirky "fixes" i heard about...toggling on and off mouse keys, etc...those seem to only help other people in small numbers. I'm thinking I should take it to apple but I am concerned about the cost. I can't seem to find out more about this tier level cost saving measure for fixing macbook pro mid-2012. Wish i could get some estimates before I trek out there with this thing. I read that one person in another country after a long phone call got repairs done FREE but that tech I spoke with didn't seem interested in that. Any advice would be greatly appreciated. Thanks in advance.
HELLO. I just want to report that after months of agonizing, abandoning, and then going back to trying things like SMC/PRAM resetting, reinstalling O/S, and popping out keys now and then to clean, I decided to wait until I had uninterrupted time in a perfectly sunlit room. I waited until my husband left essentially since i'm too easily distracted. I got every kind of key popping tool I could come up with. I'm STILL scared of doing it because I don't know if static can screw things up. I ended up using special toothpicks...the fancy ones...the triangular shaped G.U.M. ones, a little spatula for women's facial wax (don't ask), new unused eyeshadow brushes, super strong reading glasses, tweezers, and yes, my Dyson vacuum. I figured since it was seeming like I was going to have to pay through the nose to repair anyway, may as well risk causing the damage and hope they don't tell me what damage I caused with this step and how much this step cost me extra in dollars.
Well...somewhere I read in response to those who's " r-t-y-u-i" keys intermittently not responding or lagging, someone suggested cleaning the "e" key...They said they learned that the "E" key can be dirty, affecting other keys, even though "E" types fine. Essentially, the advice was to clean keys to the left of the problem keys. It's a strange problem because the keys intermittently don't work but I eventually figured out that they DID work, they just LAGGED...LAGGED BY A LOT OF SECONDS sometimes but DID work. Puzzling. Felt so much like a software issue since El Capitan was installed just prior to the problem. Then I though well...swollen battery seems to make sense too.. I seem to remember a great deal of HEAT that seemed not right...so much so that I felt it was wise to take the bottom protective add-on case off my macbook pro. I still have the top one on but I thought the plastic was perhaps insulating it too much even though it's made by apple. Heat still occurred. I recall even downloading an app for gamers...smc fan controller to control your fan when you want to cool things off. That seemed to help. I wondered if El Capitan's upgrade was incompatible with that app. Don't know.
Back to the "E" key. There it was...a cat hair. I cleaned a few other keys in that row..."P" key still loose since I cracked something on many of my cleanings but it's been about three days and the problem has NOT returned. I am including ALL this info in the hopes that others with the same problem can find this SOLVED post through keyword searches that appear in this wordy post. So, in conclusion, a key that works might be dirty and making other keys that are clean NOT work. Hope this all makes sense.