my TiVo rec video but no audio

I would go to TiVo’s website.

I have TiVo and thats what I would do in your situation.

The audio cables between the TiVo and the TV (or stereo system) might be wrong, meaning you are in fact recording sound, but you can’t hear it. Check that the red and white cables (the audio cables) are plugged in to the ‘audio out’ of the back of the TiVo and the ‘audio in’ of the TV.

Can you tell us more about your source? Are you sat or cable? Do you have a converter box in between the wall and the tivo?