Hello. I have an Asus Laptop that I recently bought a few weeks ago, and I had just opened it up because I had a metal piece stuck inside my audio/headphone jack and I had opened the laptop up to examine what was wrong, and when I re-screwed the cover back on, now when I boot up my PC, the keys are not working properly at all. Wth happened?
How to re-plug the cables depend on the type of connectors were used. For modern devices, direct flat-flex connectors are quite common and for those, you need to lift the locking bar to release the ribbon and make re-insertion easier. That bar may be located either in front (the side the ribbon comes in from) or in the back depending on the type. If you don't undo the bar, you may end up ripping the ribbon off while trying to unplug it or warping it while trying to plug it back in.
If it uses some other connector type with non-obvious retention mechanism, you may want to take a few minutes to look it up to avoid mangling it.