I was able to pickup a nice SX-1010 today. It's very dirty but untouched inside. The only sign of previous work is that the protection relay has been bypassed by someone before me. Other than that it looks untouched. It seems like these SX-x3x series receivers like me. I'm up to three now. SX-636, SX-737, and SX-1010. I cleaned the switches and powered up on the DBT. To my surprise the protection relay clicked right away. Too bad it's bypassed! The DC offset seems good. One amp board has 20mV bias. The other other amp board is stuck at 0mV. I think I must have a bad output transistor? The amp does play through speakers, but it seems distorted and week though the channel with no bias. It smells like walking into an old cabin that no one has been inside of for ten years. I'm almost done with the restore of my SX-737. I think this one will be next. The SX-737 has went well and I hope this will be a fun project.