I own a Yamaha receiver, which is about 6 years-old now. I just moved and when I took it out of the box, and set everything up -- to my surprise -- it wasn't powering the speakers, while everything was turning on.
I understand that something could be wrong with the amp; however, I hear the sub just fine but the speakers themselves are not, no matter how high
I turn them up, there is no sound.
of course , any thing is fixable . what is it going to cost and who is going to carry out the repair. every receiver i have ever seen had at least one fuse or two or three some right on the back , and others sometimes inside by the power supply. if you don't know a lot about electronics check the fuses that is about the easiest fix there could be . if you see any thing inside that looks burnt , discolored , corroded or a cracked circuit board it is likely that may be the problem. it sounds to me as if you have a problem with the amplifier portion of this receiver , if you plug in head phones and get sound that would confirm that the preamp is functional and the amplifier is not.
your circumstances , my guess would be that there will be a cracked circuit board inside, it may not be easy to spot either, if you do take this apart you should in preparation unplug this while it is on to discharge the device as it will store an electrical charge in the electronics as do most modern electronics .