Go to
http://support.tivo.com/app/answers/detail/a_id/294/kw/code%20search/c/105/r_id/100041 and under Programming TV Power, Volume and Mute, click on "show the steps".
Follow the instructions given.
The RCA remote codes are 0163, 0001, 0004, 0006, 0011, 0029, 0030, 0057, 0071, 0133, 0145, 0106, 0171, 0231, 0232, and 2210.
Try each of these codes one at a time (as per instructions) until you find one that works.
This link also gives instructions on what to do if none of the above codes work.
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