you forgot to see the AVR works prefectly using speakers
8,6 or 4 Ohms Z, selected to right ohms the switch.
does it? if yes he below is moot,
why do that.
it there is sound source running, and loud and you have no speakers there, that can damage some amps.
so don't do that, some AVR have no error code, protection lamp
just relay clicks
your AVR is really old a sea of RCA jacks on the rear.
there is no need to run any amp ever, lacking a set of speakers.
7.1, does have rules here, no sure me miniumum rules.
may be 2 are required min. (the selected set A or B)
what I do is read the manual first .
found it googled in 1second flat.
The protection circuitry has been
Make sure all speaker wire connections on this unit
and on all speakers are secure and that the wire for
each connection does not touch anything other than
its respective connection
Check that the impedance selector setting is correct
I have repaired amps (AVR and others back to 1960s)
the protects circuits trip 1 or 3 ways or both (tech facts)
- over currant the PA (power amps at speaker jacks)
- or imbalanced driver transistor pair (push pull or class A)
- or overvoltages there. now.
so if it has way 3, and he source is full volume and heavy metal band then it trips. no speakers due to output is way too high.
an amp that can do 1000w peak can do 90v peak to a speaker.
yours is 95watts RMS each , peak is not stated. nor is protects stated in absolute terms.
answer 1,. turn off all sources and volume down to run no speakers.
also it told you power off to connect. speakers.
when you do not power on the surge in the PC can be huge
so it tells not to do that.