I've had the unit for about 2 years now, and it's been very nice.
I mostly have the unit either on or in standby mode.
Yesterday, I switched off the 4 first channels and on the last two, to try a pair of speakers.
After that was done, I switched off the channels 7-8 and switched on channels 1 through 4.
But there was no sound. Nothing. I knew the rest of the chain was working as it should, and tested it again with the last 2 channels.
So, the first 4 channels were dead. Little LEDs inside seemed on, but no heat came from the left side of the unit.
So, I completely turned it off, took out the power cable and let it sit for the night.
This morning, I plugged it back on, and to my relief, the first 4 channels were alive again and working well.
Yikes! That was a scare!
So, to owners of the unit, if this happens to you, try to disconnect the unit completely for a while and reconnect later.
I have no idea why it would work, but it did and I was glad.