OK - two Marantz receivers in a row have been on my bench, and both have tuner issues. On the previous 2216B I recapped the tuner and caused my own problem. On this 2220B I HAVE NOT touched the tuner at all. This issue is a "no stereo light" in FM mode. The Stereo light illuminates when I switch the selector to AUX, so the bulb is good. I get good reception and what seems like a strong signal, but no Stereo light. Depressing and releasing the Mono button does not give me an audible difference is signal sound. I checked Pin 6 on IC H301 via TP J305, and there is 10v present (schematic says 9.7) so that's good. So what am I left with? The only components I see between that 10v on pin 6 and the light are the selector switch and the FM muting switch. I've De-Oxit'ed both, but maybe they need some more? I went ahead and recapped and overhauled the receiver, and it sounds great. But I'd like to square the tuner away, as I plan on gifting this to a friend for his garage stereo. I do not have an oscilloscope or frequency generator..... are there any simple checks, tweaks, or troubleshooting that I can do in the hopes of getting the tuner to work properly?