I have a Technics SA-AX920 receiver. With or without speakers connected, I get the "overload" error message after it's been on about 10 minutes (no sgnal). This happens even with the cover off, and the hottest component is the power transforner at about 105 degree F.
To help all of us who are having this problem, we need someone to tell us what the system is actually mesuring. Is it, current? Is it temperature? What are the sensors and where are they?
The output transistors are shorted, take to service center. $$$ to repair.