Normally, a cable box doesn't respond to voume and mute commands, and instead the remote sends those three signals to the TV, or if you've set it up that way, to a receiver.

If you really want help, please put in some effort. Please describe
1) what happened when you tried the factory reset (981?) command. Did the remote blink 4 times?
2) If you press the TV button, and then press mute, does the TV button blink? Does it blink when you press Mute? Different behavior while in Cable mode?
3) Does the Mute and Page+- buttons show flashes when looking at the emitters with a digital camera?