[NostalgiaRadioTime]

I think Chas stumbled on to something I hadn't even thought about, because I use the stuff so often and never encountered this before. I think this could possibly be DeOxit residue in the volume control and/or the tube sockets. It's a good cleaner, but does not evaporate and takes a long time to dry. That may explain why the set is now playing fine at longer intervals before it starts acting up. The DeOxit may be starting to dry in the control, but still slowly seeping into places where it's causing problems. I took some fast drying WD-40 Specialist contact cleaner and flushed it out, spraying it into the control and letting it run out, then following with a gentle blast of compressed air (not from an air compressor but from one of those aerosol cans...making sure it was just air and not a blast of liquid these things sometimes surprise you with). I did the same thing with the tube sockets. I'm going to let it dry overnight and see if I have any improvement.

Unfortunately, I did the same thing to the second chassis I have, and I suspect that the DeOxit is causing problems there too. So I did the same flushing procedure to this chassis as well. I didn't try the set prior to changing out the e-caps because there was some dark residue all over the bottom of the chassis around the capacitor can connections, seeming to indicate there was some smoke or possibly even a flame going on there! It didn't look safe so I changed them out. But those, and the leaky .1 wax cap (C10) with the bulged ends is all I changed. I was careful in installing them to make sure I had solid connections. I even took a magnifying glass to look over each solder joint! But yes the negative of the two electrolytics are connected to the same common chassis ground point.

I appreciate greatly all of the suggestions and will definitely explore them further if the flushing doesn't clear up the problem. If it does turn out to be DeOxit residue causing all of this grief, well I just learned a valuable lesson to stick with the stuff that evaporates whenever possible. At least use that first and if the controls are still dirty, then use DeOxit but make I give it plenty enough time to dry!

You are so right...intermittents ARE a nightmare! I'll let you know what I discover tomorrow.