I just wanted to exhaust all options, and you are correct, as I suspected this has come down to a hardware issue. I don’t think there is a way out other than hardware replacement at this point. You could replace the screen only, or APIM only, but I think you’ll find it might be cheaper to replace both as a unit than buying each one of these separately. Just stay away from the APIM’s that indicate they are from China, as those may not be as they seem.
You do not need to have the unit programmed by anyone, as you have the ability to do that and make the changes you want. So remember that when making an offer, especially on eBay.
I used a guy on Facebook and that went smooth. One thing I did learn is know what APIM part number they are sending you. While mine works fine it was an older one that will not support some of the latter features sadly.