rocknroller
Active Member
Have this receiver with no FM audio at all (AM is fine). Not faint, no static - nothing. While I won't rule out the possibility it needs an FM alignment, my intuition tells me this is more of a part failure issue. See attached circuit diagram. My issue is that I don't understand (have the appropriate knowledge) on FM circuit design, so I'm not really clear where the signal is flowing and what is expected. With an audio tester, I hear tuned FM at Test point #1 (TP 1). I also hear an appropriately attenuated signal just past R102. However, I do not hear any audio at Test point 201 (not sure if I'm supposed to) nor do I hear any up to the right at R105. Again - not sure I'm supposed to but thought that may have been where the audio signal travels. If so, that might indicate that strange looking CF103 in between is bad.
I guess i hoping someone can explain where the audio is expected to flow so I can continue to try and debug where it's getting lost. Any thoughts on next steps of things to check would be greatly appreciated as well.
I guess i hoping someone can explain where the audio is expected to flow so I can continue to try and debug where it's getting lost. Any thoughts on next steps of things to check would be greatly appreciated as well.