Answer to "Internal keyboard and trackpad not working"So I had this exact thing happen on my 2015 retina 13 inch MBP. Last time, I had to check the battery that swelled and didn't charge ... I swapped battery out myself and voila ... mac booted with keyboard and mouse support. About 2 months later with moderate use, trackpad and keyboard stopped working again. Took the back off, saw the battery was okay and cable was okay. After taking back off, mouse and keyboard started working again. Try this first, may buy you a few months before you have to do it again. Update - 1 screwing back plate back on renders trackpad and keyboard useless again. Took back off and worked again. It may be a cord insulation problem that a revision of the cable itself solves. Will try to insulate cable from shell but so far workin cover unscrewed but still affixed to bottom. Update - 2 Not an insulation but pressure problem. Too much pressure is being put on that ribbon cable really sucks.