If any or all of your Bose Surround Sound speakers are not producing any sound, this does not necessarily mean that they are defective. There are a number of things that can cause such an issue, and they are often very simple problems like loose wiring. You can correct the problem yourself, and it doesn't take long.
Sound From Front Speakers but Not Rear Speakers
Make sure the rear speakers have not come unplugged. The speaker cable should be plugged into its corresponding port on the back of the Bose receiver. Make sure the left rear speaker is not plugged into the right rear speaker port and vice versa.
Check the Audio function on your Bose system and make sure it is set to "Surround Sound" or "Home Theater" mode. It is possible that not having it set to this mode will cause sound to come from the front speakers but not the rear. There should be a button on your Bose remote control that activates the surround-sound mode.
Check the audio specifications for the program you are watching. If you are watching a DVD, hit the "Audio" button on the DVD remote control. If it is set for 2.0 Audio, it will not play in true surround sound. This is why only the front speakers will produce audio. If it's possible, change the audio setting to 5.1 surround sound. If your DVD does not have 5.1 audio available (most do, especially newer ones), then you will not be able to watch the DVD in surround sound. If you are watching a TV program, a caption will typically appear at the beginning of the program to indicate that it is available in surround sound. If no such caption appears, and you have tried all of the above methods, then it's safe to assume that whatever you are watching is not being broadcast in surround sound.
No Sound From Any Speakers
Make sure that all speakers are plugged in where they need to be. The ports for each speaker should be marked accordingly, right for right, left for left, center for center, etc. If necessary, wiggle some of the cables and wires to make sure there is no short. If this is the case, the cable, wire or the speaker itself, might need to be replaced. You do not need to check the power sources or plug ins for the Bose receiver, because if it is not plugged in correctly the system will not turn on. This is assuming that the receiver is turned on but no sound is coming from the speakers.
Check the "Input" source on your TV. Most TVs generally have an "Input 1" and "Input 2" function. Typically Input 1 is reserved for component or HDMI hookups, while Input 2 is typically for standard composite AV hookups. Your Bose Surround Sound System will work through either one of these; it depends on what kind of hookups you use for your TV or DVD player. It should say either "Input 1 (Surround)" or "Input 2 (Surround)" for your Bose system.
Mute the TV or turn the volume all the way down. If you have sound coming from any other exterior sources (such as a cable box), turn those down as well. If the TV or cable box volume is turned up too loud, it can trick the ears and make it sound as though no sound is coming from the speakers.
If there is sound coming from the rear speakers but not the front speakers, then the front speakers are most likely not hooked up properly. Again, make sure the right speaker plugs into the port labeled "Right" and so forth. If none of the above suggestions fix the problem, you should contact Bose Customer Service.