Hi 'Shoez and welcome to thecarversite.com.
Can't say on the tuner, but the goto guy for the amp is @Nahash5150. You can contact him via private message here, or you can check out all his services at
https://nelionaudio.com
and for your amp here:
https://nelionaudio.com/index.php?/services.html/carver/carver-amplifiers/carver-m-15t-mkii-restore-and-upgrade-r20/
There are some here that have worked on tuners, and you might be able to find some clues using the site search function. Here's a link to a thread where a member had a similar tuner problem, and the fix:
I hope that helps, and again, welcome, congrats on the new digs. Oh, and once you get to Novice status, please consider uploading some pics of your gear in the Members Systems area. We all like pics of all kinds of gear!