I assume the RF module (that has the power button and ring of lights) communicates with controllers. I am unable to add controllers to my modified system (tried two different RF boards). when I press the learn button the rings on the RF module and on the controller go through the searching pattern but never finds and adds the new controller. I also cannot control the xbox with the media remote which I believe is IR. Any ideas?

so there is no interference or your not holding the button on the controller + IR port on your 360 is on? if you eliminated all of those things then i would say your 360 is going, is it old? if not might want to have microsoft look at it and have it fixed

what do you mean by modified system?

http://forums.xbox-scene.com/index.php?showtopic=690802
that is the system. Does the controller us the IR or RF?

you need to use contacts at the back of the board like the xecuter glow mod uses its more reliable