Is Apple Siri Remote parts paired?

I have two 4k Siri Remotes, one with a cracked touchpad and other with water damage. I want to swap broken touchpad and buttons (front cover) with one that is not cracked. But doesn’t work after swapping. Is there parts pairing between touchpad and main logic board of Siri Remote and can I swap out a chip to get working. Love to tinker either electronics and fix things rather than just send to landfill or recycle. By the way it’s the black remote