Hi,
My B&K 1211A color pattern generator is defective. I can not adjust the channel A and Channel B and chroma frequencies. As long as I disconnect the variable capacitor for channel B, the channel A and chroma frequencies can adjust to the specific values. If I re-connect the variable capacitor, the unit not working anymore. I change the variable capacitor for channel B but still act same. If anyone in this news group has the schematic or any ideas for troubleshooting. All the TTL IC have been test and ok and switches all fine.
Thanks