Jay Hennigan was correct, pins 6 & 7 on the 6X4 tube socket were shorting. I replaced the socket and C514 is now stable. However, one of the OA2 tubes glows bright blue at the base when I turn on the unit as if the tube is shorting. The issue follows the tube when I switch the OA2's. Has anyone seen this issue on an OA2? I'm assuming I need to replace both tubes before I put the TSU back in the jukebox. Thanks --jerold k