Brightness keys and webcam do not work after screen replacement

Hi all!

I recently replaced the screen on my Thinkpad t450s, which I bought second hand but I believe it was an original Lenovo product as far as I could ascertain.

After seemingly successfully replacing the screen, the brightness keys on the keyboard no longer work, nor is there an option in settings or the control panel, and my webcam pulses on and off when I try to use it.

The screen brightness is normal so I believe I haven’t shorted anything out, and I disconnected both batteries before replacing the screen as a precaution.

Is it a dodgy screen?

Any help would be greatly appreciated!

Thanks in advance,

Matt