Toslink (fiber optic) connectors not working
Try this. Put a cable between the transceiver and the receiver. Then connect a spdt switch to the transceiver's vin. The other two ends of the switch go to vcc and ground. Flip the switch, make sure the transmitter led is turning on, and then use a multimeter to test the vout pin on the receiver.







simulate this circuit &ndash; Schematic created using CircuitLab

This will tell you if the two are working. Even better, a very slow clock that you can measure would work as well. A 555 chip set up for 2hz connected to vin should cause vout to switch on and off two times a second (See: https://electronics.stackexchange.com/a/64527/17178)