Touch ID and Keyboard backlight don’t work

Hey guys,

Picked up a MacBook Air 2019 for a bargain recently. The machine has 3 issues:

1. Trackpad was glitching/not responding at times - this seems to be solved by disassembling, removing the trackpad, cleaning and reseating contacts.

1. Keyboard backlight does not work no matter what I’ve tried, cleaning contacts, resetting NVRAM etc nothing. Backlight function keys do not respond (no pop up on screen), trying to set brightness via control center immediately slides the slider back to off (left). The keyboard is fully functional though
2. Apart from the backlight, Touch ID does not work, not in safe mode, not after reset. When I try to add first fingerprint, right away it tells me “Failed: unable to complete Touch ID enrollment. Please go back and try again.” Power button works though

Now after tinkering inside the mac, I can tell that someone else’s greasy hands have definitely been inside. Stripped/missing screws, peeled tape etc. True Tone is also gone meaning either the screen or the board have been replaced.

Touch ID is not a massive issue but I wanted to find out if anyone has had a similar issue with the keyboard backlight and if that can be restored?

Thank you