Experiencing weird keyboard issues after replacing cooling fans

[Aradeid]

Laptop: HP Gaming Pavilion - 15-cx0100ng
OS: Windows 10 Pro

For a couple months, my cooling fans were very noisy. After finally saving enough money, I gave my laptop to a local repair centre to get my fans replaced. When I finally got my laptop back, a few issues appeared with the keyboard:

F5 doesn't react, whether on its own or while holding Fn. The keyboard backlight still toggles every now and then for seemingly no reason.

F6, F7, F8 work perfectly fine on their own, but do nothing if Fn is held.

L.Shift+X doesn't work, even though L.Shift works with every other button, and R.Shift+X works perfectly fine.

While holding W, E and Q aren't reacting, while holding S, A and D aren't reacting, same happens for X, Z and C. This may seem arbitrary, but it becomes a major problem during gaming. I have tested all other adjacent keys, and the aforementioned 3 are the only ones affected by this issue.

Is there any way to bring the keyboard to normal behaviour?

I don't know if the cooling fans replacement has anything to do with these issues or is just coincidental, but I mention it all just in case. I cannot return to the repair shop for questions, as I had to move countries right after recovering laptop.

The laptop is also currently missing its battery, if that is relevant in any way. 

I have checked all my drivers' state on support.hp and I have tested my keyboard with the HP PC Hardware Diagnostics. 

[itsmyname]

@Aradeid -- Is there any way to bring the keyboard to normal behaviour?

Probably not. Can you connect and use a USB keyboard while "gaming" ?

Can you find a replacement keyboard on eBay or Amazon or other similar sites?