I picked up this cb used with no mic. I was able to determine that it would receive when wired for a Midland mic and everything worked except for there was no modulation. It would receive and transmit a carrier (confirmed with a local 7 miles away) but there was no modulation. Upon advice from this same local it was advised that on older radios a cap, as opposed to an audio chip, was responsible for modulation and that I should recap the radio. I did just that and now there is no rx or TX. I confirmed the right caps, right values and right orientation. What I didn't check before install was that the new caps were indeed good ( brand new). So, after testing the original caps, which all tested good, I put the original caps back in their original locations but there is no rx/tx. PA does not work. The internal speaker produces hash but at half the volume level that it did originally. If an external speaker is connected a high pitched oscillating sound can be heard. Switching from cb to PA stops the hash on the internal speaker. If certain spots, or pots, are probed with a volt meter the sound level will increase. Switching channels of switching from cb to PA produces an audible click in the speaker. I've verified 13.8vdc at the red dots.Any and all advice is welcome. A schematic would also be great! Thank you in advance!
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