LOTR: I'm not sure what you mean. There are only 5 output posts in the back and they all have speakers connected in, if you could clarify that would be great. But I will also try to find an "auto" setting.
All right, if your 5 speakers are properly connected to their respective posts in the back of your Yamaha receiver, then you're OK. Sorry if I confused you.
* The "Auto" setting should be the one for the automatic surround decoding.
* Also, in the menu setup for the speakers, like the other guys already said here, set the speakers so they are all activated.
* Another point, press the button marked "STRAIGHT", and see what happens.
* Or this, press the button marked "EFFECT", and see what happens.
* And this, set the HDMI audio to "Auto" or "Multichannel".
* And also this, in your manual, it will be indicated how to engage the full surround mode from the 5 speakers.
** I'm sure it's one of these, just above.
When you got it, let us know.
*** Seems that they are quite few people having issues setting the multichannel mode from these Yamaha receivers. Are they that hard to set up? Must have something to do with the HDMI setting, it always does.
Other brands too are not very clear in their manuals. HDMI seems to have a lot of way to go before it can simplify our lifes. And the manufacturers are not helping much the situation, isn't?
Good luck, good night & good day,
Bob