I recently brought an old 2012 13" (33.02 cm) macbook air back to life. It had a couple of problems ranging from outdated software to a bad contact between the hard drive and the main board. I fixed these issues by installing linux and opening the computer up to resit the hard drive.
Another issue with this computer was simply that the trackpad wouldn't click. It would let me move the mouse around, and it sometimes detected when i would tap to click, but i couldn't click normally. There was no movement in the trackpad. That's what I fixed today.
It turns out that it's really easy to fix a computer! This might be more true for this 13 year old computer than more recent apple hardware. I fixed the trackpad by tightening a screw that sits bellow the battery when looking at the computer from the bottom. With a few turns of a screw, the trackpad was clicking again, and it now works perfectly on the computer!
Lesson of the story: If the consequences of potential failure aren't too high, give fixing hardware a try! Fixing a computer (or a component) can be really easy, and unless the computer's integrity is extremely important, it's worth trying to fix something. It could come down to a turn of a screw.