Welcome to the forum and I don't know of any checklist, but you might check the review on dpreview.com. They are really thorough and you can run through all of the features like they have. Be sure to check the mirror and sensor, too - my 5DII refurb had a huge thumbprint on the mirror and damage to the foam around the sensor. I didn't catch that until after the 30-day warranty, which thankfully is now 1 year. Other than that, I'd just try shooting it in all the modes and such, but generally their refurbs are often better than new - i.e. have less reported problems than brand new bodies because they've been checked out twice.