whilst not an official Tascam site, there are some experienced techs here. It would help if you told us where you are.
Oh, and welcome!
to save time, tell us what the issues are.
Well Jim may not be doing repairs yet and I am overloaded as it seems I am the only one doing these- yes other are working on them and then I get to fix those too. Gerhard in FL can work on it as he is set up. I am in Chicago area.