Pls Help Me Troubleshoot an iPhone 7 Home Button

Hello, I’ve searched the forum for this info and have read the relevant threads. I will post some photos if need be.

The situation:

— 2 iPhone 7’s

— 2 cheapo screens from this vendor

https://www.amazon.com/QTlier-Replacemen...

I used the original buttons and I don’t believe I damaged them or the ribbons in any way. Screens work great, buttons do not function.

On one phone, the button give the error “cannot use fingerprint scanner” or something like that. On the other, there is no response.

I have tried connecting these buttons back to the OG screens, and surprisingly, they don’t work. Wouldn’t that indicate that I have damaged the buttons?

So the question now is: How can I tell if I damaged the buttons?