Q: the seven center letters on keyboard do not work, d,fghjkl, i'm using an external to type this, what can I do?

Maybe some help here:

http://support.apple.com/kb/TS1381

http://support.apple.com/kb/PH10680

You may need to take for service.

anyone has found a solution for this? i have the same problem, very often, when im typing all the FGHJKL keys stop working, a few seconds later, they work again, i have removed, cleaned and replaced them.

Identical problem here.  Seems like this is not a unique problem.  Does anybody have a definitive solution?

I have the same issue (Mac Book Pro, 2012, OS X 10.8.5) with one of our Macs.  Keys work very occasionally.  Works fine with an external keyboard.  I have a genius bar appointment tomorrow morning.

I may have solved this.  This is my daughter's laptop and she was running Steam (game engine) as a 'Login Item' at startup.  I suspect, given the pattern of the non-working keys, that a game loaded with the engine and inadvertently disabled/interfered with the built-in keyboard.

I removed the startup item from the list, rebooted, and the problem was resolved.

1. Open 'System Preferences'

2. Click on 'Users & Groups'

3. If needed, click the lock to make changes (lower left).

4. Click on the 'Login Items' tab.

5. Identify any software at startup (e.g., games, game engines) that could interfere with the keyboard. 

6. Click on the item(s) in the list and then click the minus ( - ) button to remove them.

If I run Steam after startup, like any other application, the keyboard continues to work as expected.

I thought that this was odd that the keys always fail D-F-G-H-J-K-L. The keyboards on these machines have a membrane and horizontal and vertical traces. In this case here's the horizontal trace:

So the failure has to happen to the left of the L contact and would take out the entire trace to "D" but not affect the "S" and "A" keys.

These keyboards seem to be very prone to this kind of failure. I had an "S" key go wonky and the hair that caused it was microscopic!

Unfortunately if this is the failure, replacement is the only solution.

You're a genius! This worked for me!

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.

this worked.

I had the same problem but with R T Y U I O keys.

After a full 6 hours of booting into safe mode, resetting PRAM, RAM tests, resetting system management controller, keyboard preference changes, reinstalling OSX, software reinstalls I'd finally had enough...

I bashed the keyboard then lifted my macbook and dropped it from about 12" off the table. Now I wouldn't recommend this to anyone but it's worked fine for me. As you can see full keyboard functionality has been restored!! Go figure...

this worked for me also.

Happened to my KB too. T,G,B, keys not working.