My MacBook Pro A1502 (early 2015) had a bad battery which I replaced. Unfortunately the keyboard and trackpad stopped working after no matter what I did to fix it. I am now using a usb keyboard and mouse, but when I try to boot into options, or other boot options, it won’t recognize the (windows) keyboard commands. The keyboard and mouse work fine when putting in my password and operating the system, but won’t recognize during boot.