There's several Youtube Videos on restoring old computers including the CoCo, most of them come with plenty of commentary on parts that tend to fail or should b

There's several Youtube Videos on restoring old computers including the CoCo, most of them come with plenty of commentary on parts that tend to fail or should be replaced regardless of if they are working now or not. I think one of the better ones for this is Adrian's Digital Basement. And also you are in luck there was a big "SepTandy" push last month among a lot of those classic computer channels featuring Tandy computers including the CoCo, so the odds of finding up-to-date information is really good.