MacBook Air internal keyboard and trackpad freezing I have a MacBook Air a1369 running IOS 10.11.4 with a 1.7 ghz i5 processor. I use the Mac fine, but after about 30 to 40 minutes of usage, and I put it to sleep, after it wakes, the trackpad and keyboard are unresponsive. Only the power buttons work. However, if I connect an external keyboard and mouse, then work perfectly (I'm actually writing this question with my external keyboard. I also get a Bluetooth setup assistant pop up window asking me if I want to connect a Bluetooth keyboard and mouse.

additional information>
Apple Internal Keyboard / Trackpad:

  Product ID: 0x024c
  Vendor ID: 0x05ac  (Apple Inc.)
  Version: 2.09
  Speed: Up to 12 Mb/sec
  Manufacturer: Apple Inc.
  Location ID: 0xfa120000 / 3
  Current Available (mA): 1000
  Current Required (mA): 40
  Extra Operating Current (mA): 0
  Built-In: Yes


Some other findings:

The keys can sometimes wake the computer, but as soon as it wakes up they don't work.
They don't work at boot (i.e., cmd+R, cmd+V etc do not work).
I've reinstalled Mac OS (using net recovery, cmd+opt+R). I've also reset the SMC and PRAM.
Disconnecting Bluetooth and USB devices do not help.
The problem is uncorrelated with how warm the computer is (i.e., it's not an expanding battery problem).

I've gotten my keyboard changed and also put in a new battery but its not helping. I can obviously use it with the external mouse&amp;keyboard, but it takes away the magic from using a Mac. Plus is not convenient as a I need to have these additional components connected to it.

Any help or guide would be appreciated.

MacBook Air, OS X El Capitan (10.11.4)
You pretty much covered all the troubleshooting bases.  Have you tried to wipe/reinstall OSX?  

Next step would be to bring it back to the Apple store for diagnostics or further repair.  This is not normal.