03-10-2016, 09:31 AM
Another thing to be aware of is that large wire wound resistor with the taps. I don't know if you replaced yours or not when you restored, but I had one on a model 70 that gave me fits. It would do about the same thing your 90 is doing. It was highly intermittent, and took me weeks to finally catch it in the act with test equipment in place. I replaced the bad section and it has been working. I need to replace the whole thing. It also feeds the screen grids on the 24 tubes (in a model 70). I don't know if it is the same on the 90 or not. A couple of notes: 1. The resistor looked kind of rough, like it has been rather warm at some time, instead of smooth and shiny. 2. I found the problem by measuring the cathode current of the 24a tubes and lots of patience.
If I could find the place called "Somewhere", I could find "Anything"
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
