How do I connect my Vizio TV to a new Magnavox DVR/VCR combo. I'm a Comcast user.

Have you checked the user manuals for the equipment? If you can't locate the printed ones, some manufacturers make manuals available for download from their web sites. There are often diagrams in the manuals. The VCR/DVD recorder manual might be the most informative.

If you recently acquired a high definition TV or a high definition ready TV you might want to consider replacing the analog or standard definition rental digital cable converter with a high definition model. Some cable companies allow you to exchange converters at their walk up customer service centers. Policies vary, but some cable companies charge the same monthly rental fee for high definition converters as they do for standard definition converters

With a high definition converter you might be able to connect the converter's composite video output to the VCR/DVD recorder combo (is it limited to standard definition recording?) and one of the converter's high definition outputs (HDMI or component) to the TV's inputs. You can than connect the VCR/DVD recorder's outputs to the TV. Component connections may provide better images than composite if the VCR/DVD recorder and the TV offer a choice of connection types.

Your ability to record a different channel from the one you are watching might be limited. With some additional RF (coaxial cable) connections between the cable outlet and the TV and/or VCR/DVD recorder you may be able to bypass the cable converter to simultaneously view and record a limited number of cable channels.

Please provide some feedback about how much you are able to figure out. Detailed assistance might require equipment model numbers and knowing which metropolitan area you are living in.