Hi. Thanks for the couple of members who tried to assist with my sound issues. For the record, I just received a NOS Pokey chip, installed into the Concerto cartridge, and voila, I have sound! Somehow the working Pokey chip I removed from an old 5200, must have gone bad (though, I still am puzzled about that)? Anyway, I haven't had the opportunity to test everything, but all is good in the world right now for me. Thanks again!