MacBook Pro Early 2015 Keyboard and Mouse Unresponsive

Hi all, my Macbook pro (Retina, 13-inch, Early 2015, 2.9 GHz Dual-Core Intel Core i5 and macOS Cataline 10.15.4) has two serious problems for over 6 months.

The keyboard and trackpad/mouse (the thing that's in-built, I don't know the name) both do not work. For many weeks I was locked out of entering my computer because I could not type, nor move my mouse to log-in. It said it could not find a Bluetooth device to connect to, which is weird as the keyboard and mouse are part of the computer, not an external bluetooth device.

I gave up and resorted to using an older Macbook Air to do my work but recently I thought I would try seeing if I could fix the problem with my Macbook Pro. I now use a Magic Keyboard and a trackpad (both via bluetooth) and so I am able to control my computer without using its inbuilt keyboard and mouse.

However, this is very impractical and annoying for me as I have to carry around two bluetooth devices wherever I go with my Macbook.

I have tried shutting down, restarting, shutting down and pressing option shift keys, and still have had no success on a functioning keyboard or mouse.

What can I do? Please help, anything is much appreciated!

Thank you so much,

Sofia