Few simple but oft-overlooked things first:

1. There's a TAPE 2 (monitor) button on the front panel. Make sure it's not engaged.

2. Depending on the device you have hooked up, make sure you check the Digital input button so you're not forcing the receiver to the wrong digital input, or that you're not looking to a digital input when the source is analog.

3. Make sure you didn't plug the fronts into "Speakers B" and that "Speakers A" is selected.

Mind Over Matt'er - Technology musings, opinion, and more straight from TechLore's head geek.

Hmmm...

Can you share anything else you've tried?

When you set the receiver to TUNER, do you get anything out of the speakers? Even static?

Mind Over Matt'er - Technology musings, opinion, and more straight from TechLore's head geek.

If you are hearing static, the outputs are OK. Is this a new unit? Are there pre-amp outputs in the back? If so, try connecting from those outputs to another amp. Sound=preamp/switching sections working OK. If nothing, then the pre-amp section has a problem. Check for sound at the tape-out jacks. See if the inputs switch. If not, than I'd suspect the internal electronic switching chip. It may be a TC9163 (from memory).
Keep us posted.
Dan