Hi there, I have been scouring the net for a solution to my issue, and none of the responses have worked so I hoped I might be able to get some new advice. I opened the lid of my A1398 (2012 Macbook Pro 15" Retina, 256gb SSD) this morning and the trackpad and keyboard had stopped working. I have tried the following to get it working again: - SMC Reset using Option-Control-Shift - NVRAM Reset using Command-Option-P-R - Reinstalling El Capitan 10.11.3 over the old install - Using Disk Utility to wipe the Mac HDD and then install a fresh El Capitan 10.11.3 - Disabling the Internal keyboard and then re-enabling it. I have attached a video which shows a strange flickering in the Keyboard System Preferences,. Not included in the video is when you go to change the modifiers, and you drop the menu down while the F-Key options that is flashing is displayed, you can get the Keyboard/Trackpad to show up. I know other people have had these issues in El Capitan but it's very frustrating. Any ideas?