I was sitting there enjoying my favorite Fleetwood Mac through the crack and 650s and all of a sudden the song fades out in the middle (although I must say it was a nice sounding fade out!).
Anyway, the tubes aren't glowing anymore when it's on, and obviously no sound. Also, this happened a couple times in this listening session, where the sound would begin to fade in both ears for a moment and then come back. Then finally it just faded completely as described above and never came back.
Any help with diagnosis would be much appreciated. I flipped it over to have a look and everything looks to me at first sight to be in place and in good shape...
Thanks in advance for any suggestion/tips/help figuring out how to get me back to crack.