Owning an optical audio cable, often referred to as Toslink cable since they were originally developed by Toshiba, can be a very good way of connecting components in your system, but it’s not always a perfect solution. An optical audio cable can be more prone to problems than a coaxial cable so you have to treat it carefully. Although it might look as sturdy as others, a Toslink cable is actually comprised of delicate wires and fibers.
One of the most common problems with an optical audio cable is breakage. The breakage occurs inside the protective sheath and is not easily visible to the naked eye. If your cable stops working, there’s a very good chance that this will be the cause. Unfortunately, the cable can be broken easily. The simple acts of bending it, twisting it, or even standing on it can cause irreparable damage. When this happens, there’s nothing you can do but buy a new cable.
Optical cables use a special connector when used with other components. It’s important that you insert these properly and that you don’t tighten them too much. They are much more sensitive than coaxial cables and you will need to apply less pressure. If the connector isn’t inserted correctly, the components will not connect; if the connection is over-tightened, it’s liable to break.
You also you need to be certain that you have the Toslink cable plugged into the correct connection. If there’s no sound, for instance, it may be plugged into the wrong connection. This could be something as simple as connecting to an 'out' connection instead of an 'in' connection. You should be aware that 'digital out' and 'optical out' can be exactly the same thing as long as the special connector will fit.
If your audio set-up requires you to bend cables to follow the line of a wall, and your optical audio cable stops working, the bend has likely caused a break in the cable.
4. No Light
An optical audio cable should have a red light at each of the connectors when it’s in place and working correctly. If you don’t see the light at either of the ends, the cable isn’t connected properly, is broken, or you might just have a faulty cable. The light is an indicator of a problem, rather than being the problem itself, unless the connector on the component is broken.
5. Audio Source
Another common problem is that the audio source on the receiver might not be properly established. It will need to be set to either 'optical in' or 'digital in' in order to work properly. Failure to do this, even though the connections might be perfectly good, will result in no sound. A similar thing can happen with computers if the correct audio source isn’t selected.