I just got my TX-NR709 in to replace an old Yamaha HTR-5750. I am so looking forward to being able to have more than one HDMI device. I was worried that my old Sceptre TV wouldn't play well with the receiver's HDMI, so the first thing I did was plug in the TV via HDMI first, and that worked. So I pulled out my old cables, hooked up the new 709, plugged it in, and turned it on.
The dreaded "CHECK SP WIRE" appeared. So I disconnected everything again, waited 15 minutes, and tried to turn it back on. POP && SMOKE. Yay me!
I assume that this must've been an internal short, since nothing was connected when it smoked. Amazon is sending me a replacement... should arrive on Saturday. Here's hoping the new one works better!