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doing some resistance checks of the sync amp seems to have paid off. The control grid showed no connection to anything.tracing back there is a coil that come one of the detector diodes. it was a poor solder joint, a solder blob on the pcb,with the coil wire next to it. I suppose it could have been that way from day one, perhaps over time it opened up. Lots of flux around on these boards again looks all original. Anyhow I corrected the poor solder joint, and retested the resistance, looks good now, so will reinstall the chassis later today.
I recall I was getting old looking video to the separater, but without a working set to compare its hard to tell. The sams are really not the best for showing waveforms.
I prob would have picked up on this much sooner if I had bothered to examine the PCB up close in a strong light. the poor solder joint was pretty obvious...
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