11-29-2018, 02:09 PM
For those of us who are following from are recliners at home the Sam's for this set can be found here: https://www.google.com/url?sa=i&rct=j&q=...2764921355 as a pdf file.
< have a nice bright glow except for the 2 tubes connected to the fly-back the transformer
The two tube connected to the flyback are the 1B3 and the 6DQ6. The 1B3 has a small filament and doesn't glow brightly and it's hidden by the plate structure of the tube. To test it measure the resistance at the base of the tube w/it out of it's socket from pin2 to pin 7. Should show a few ohms if open tube is toast. Do likewise with the 6DQ6 measuring pins 2 and 7 I think they are going to be open and in that case you'll need a replacement. Between those two tube they generate the 10,000vdc or so to light the screen of the crt. I would be normal if there is a failure there then the crt screen isn't going to be obliged to light.
> T2 is buzzing,
May or not normal have never had a working Predicta. Can tell you if c-44 is shorted could very likely damage T-2.
> I want to see if I can just fix this set rather than do a full recap.
I have a question for you. How many times would you like to remove the main circuit and it's 30 some odd wires to keep replacing failing caps as they die one by one??
A typical service on these set would include replacement of all foil/paper caps, checking resistor for tolerance and replacing out of spec ones, testing for weak tubes, cleaning the circuit board as they do get very dirty from dust and dirt falling into the vent holes. After that then start the troubleshooting.
GL
< have a nice bright glow except for the 2 tubes connected to the fly-back the transformer
The two tube connected to the flyback are the 1B3 and the 6DQ6. The 1B3 has a small filament and doesn't glow brightly and it's hidden by the plate structure of the tube. To test it measure the resistance at the base of the tube w/it out of it's socket from pin2 to pin 7. Should show a few ohms if open tube is toast. Do likewise with the 6DQ6 measuring pins 2 and 7 I think they are going to be open and in that case you'll need a replacement. Between those two tube they generate the 10,000vdc or so to light the screen of the crt. I would be normal if there is a failure there then the crt screen isn't going to be obliged to light.
> T2 is buzzing,
May or not normal have never had a working Predicta. Can tell you if c-44 is shorted could very likely damage T-2.
> I want to see if I can just fix this set rather than do a full recap.
I have a question for you. How many times would you like to remove the main circuit and it's 30 some odd wires to keep replacing failing caps as they die one by one??
A typical service on these set would include replacement of all foil/paper caps, checking resistor for tolerance and replacing out of spec ones, testing for weak tubes, cleaning the circuit board as they do get very dirty from dust and dirt falling into the vent holes. After that then start the troubleshooting.
GL
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
