1. the emitters have to be placed directly over the IR eye of the piece of equipment. You can't just play the emitter anywhere. Take a flashlight and shine it on the front of the equipment and you should be able to determine where the eye is.

2. A while back, there was a run of bad emitters that were not opaque on the rear and therefore, the signal did not pass through. See if you can see the light on the emitter flash from the rear of the emitter to ensure you have good emitters.