The Bose 321 is a compact home theatre system that includes a combination receiver/DVD player, a pair of small Bose speakers and a subwoofer. The system appeals to people living in smaller apartments who want to get good theatre quality sound without running a lot of wires around the apartment.
Issues that can crop up with the Bose 321 are no power or bad sound. A power surge is capable of knocking out the Bose 321; check for this by unplugging the unit, waiting 60 seconds and plugging it back in so that it can reset itself. Make sure the appropriate input is selected when you turn it back on (DVD, CD, AUX).
Some issues with sound can be no sound or distorted sound. Make sure the speaker wires are not damaged and that the polarity of each wire is connected to the same polarity on both ends (receiver and speaker end). If you have no sound, try turning the volume up to see if the volume was at zero. Make sure the Mute button is not on; press it on the remote to check it. Also, check to make sure the audio outputs are correct on the component you are trying to play. Check that the system is work by cycling through different inputs (FM, AM, TV); if you have sound from some inputs but not all, the connections between components are probably not set correctly.
Picture problems are almost always the result of connection issues. If you have no picture, make sure the TV is set to the proper input for where you have connected your 321. If the picture is black and white from a DVD, you have probably not connected the component video cables (red, yellow, blue) correctly; make sure you have plugged them into the corresponding connection jacks on the 321 and the TV. It is also possible that you do not have the correct TV standard set; go into the System Menu and make sure NTSC is the video output selected (in Europe, it should be PAL).