My First Predicta

[Chris K]

Originally Posted by bandersen

Well some of those readings are way off. I'd start by tracing out the 12CA5. Is pin 2 grounded accidentally? Pin 2 and 5 should be connected together so you should have gotten identical readings but you didn't?

Also check that the primary on the audio output transformer is good. That supplies the plate voltage to the 12CA5

Audio output primary is good, 285 ohms. The reading on pin 2 is correct at zero. Checked several times. I thought I might get away with not removing the board but it's looking like I might need to.

[Chris K]

So I pulled the board. At some point, the socket for the sync sep was replaced. Lousy job too. All the pins have continuity with the traces on the board except pin 2. In fact, the board is so discolored from flux and heat, I can't even see where it goes. In the schematic, pin 2 is the screen of the 9BR7 and it feeds into the K2 couplate. I do not have continuity between the pin 2 solder tab and the tab just to the right and above which would be the more likely candidate for continuity...again, the board is so fouled, I can't see if that's the case. No problem jumping the pin to another spot but I don't want to jump to the wrong spot. Anyone have any ideas?