Fender Pro Tube Twin Amp in for a service and to cure a “Rattle”4 6L6 tubes in a cageRattle turned out to be from the cage around the output tubes. One end (by the reverb transformer) was bent in slightly and rattled on the valve seat.Tubes freed up for testing (all good!)Gut shots… PCB based designs with switch relays and semiconductors (not in the signal path)Nice bias set controls so the bias can be set while the amp is in it’s case. Minor tweak required but pretty good when she came inLike the decal being upside down to look correct with the amp in the chassis!