Home button not working

Hi,

I purchased an iPad described as “badly cracked screen but everything else working perfectly”

When I received it I discovered the home button wasn’t working. I wasn’t too worried as I noted a hole in screen above home button ribbon cable, and I could just order a screen with a button.

After changing screen I have found it is still not working!

Q1. Could I test it with a home button from an iPad 7? Or would that cause damage/not work anyway? (I ask because I have one that I could try)

Q2. If it's not the home button, how hard/easy would it likely by to have problem diagnosed and fixed? The connector looks fine to my eye.

Any advise on course of action would be appreciated

Thanks