Looks like you are still here... From a very old thread troubleshooting a Heathkit AR-1500a: http://audiokarma.org/forums/index.php?threads/heathkit-ar-1500a-troubleshooting.658255/#post-8772540 You mention you have a .pdf of the AR-1500a schematic. I'm working on one I built back in '71 and a schematic would make it easier. Do you still have that? Could I get a copy? Please?