I ran across a Marantz SR6000G at a local thrift store for $20, so I picked it up to play with.
It powers up, but appears to be stuck in protect mode ("Protector" as it's labeled). Naturally this means no sound and I'm hoping that it's something I can fix and not a blown driver (STK module), since I don't know if you can readily get replacements.
It needs a bit of cleanup, but the tuner section seems to work (needles move as I tune even if the output section is shut down.
Any recommendations on where to start on troubleshooting the protect mode? I have multimeters, soldering skills and some knowledge, but no great knowledge or other test equipment. I'll start a cleanup and visual inspection of components looking for blown/damaged items.