How does an Optical Cable work and how do I even know if it's working?
Optical cables are made up of a thin mirrored glass tube (often called Glass Fibre Cables)
The signal is converted from a digital signal to light and is then reflected down the tube (see below diagram).
Optical cables can temporarily fail or be permanently damaged if tightly bent. A tight bend in the cable will prevent the
light from travelling through the cable.
These cables generally have an effective range of up to 6m (20ft) any longer and the signal will start to degrade. In order
to allow longer cabling a booster or a repeater will be required.
To see whether or not a cable is working connect it to the unit that will be sending the signal (i.e. the TV) and point the
opposite end towards a surface. A faint red dot should be visible if all is working.