I'd like to take this opportunity to welcome you to the forums, and say that I'm sorry to hear that you were having trouble setting up your TiVo® with your new Sony TV.
As Ernie has stated, you do not need to scan for the TiVo® it should be picked up automatically, however you do need to ensure that you're taking the right option. On my TV at home the remote has a "Source" button (others call it input or it will be a box with an arrow pointing inwards), you press this button and choose the correct HDMI port that you've connected the TiVo® to.
The only other option I can think of is, if your previous TV operated on a higher ratio than your new TV and your TiVo® is then broadcasting on a screen ratio that your new TV can't handle. In this case I'd suggest connecting a scart lead to your TV and TV, select the scart input on your TV, then work through the TiVo® menu to change the HDMI output on your TiVo®