I use Marantz AV8003/MM8003 with Martin Logan Spire, Clarity and Grotto Sub. There was no problem. Due to home shifting I closed my system. All speakers are disconnected. For checking I plugged in MM803, it does not start and the standby led rapidly blinking. I opened up the top cover just cleaned with a blower and pressed the SERVICE Switch on top of the circuit board at the back. MM8003 starts functioning normally (But FAN does not move). If I press the Factory button three leds on that card lit and FAN start blowing. But after 5-10 minutes it return back to Old rapidly blinking stage. I purchased it from Singapore and living in Bangladesh. Not possible to send to a repair center in Singapore. NEED Help.

Audio Players & Recorders - Marantz - MM8003 8Channel Amplifier