I don't get a picture now, even though I have been able to get one in the past.
Your TV may not be set to the correct input. Most TVs have an input button that says either “TV/Video,” “Input,” or “Source.” It may be on the TV or on the TV remote control. Look at your TV and TV remote and try changing the input setting.
Use the RESOLUTION button on the back of your TiVo DVR to cycle through the various video output formats.
Someone in your household may have placed the TiVo DVR in Standby mode. To return to normal mode from Standby, press either the TiVo button or the LIVE TV button on your TiVo remote.