How do I connect a combo dvd/vcr to a dish network satellite dvr/tv?

The DISH DVR/Tuner would need to accept AUX inputs, and they are generally disabled, if they exist at all. Cable boxes, as an example come fitted with all kinds of inputs like Firewire, USB, etc. They are usually never utilized.

The best way to get to have your DVD/VCR play on your TV is either to go in through the AUX on your TV, or, if it is an older version and does not have multiple AV inputs, then get a AV Switch Box or AB Switch.

You plug the cables from the DVD/VCR and DISH DVR/Tuner into one side of the switch, then connect the cable going "Out" to the "In" of your TV. If your TV is old enough to only have RF inputs, then you will need an RF AB Switch.

If your TV is newer and has regular "RCA" type plugs for Audio and Video, then you will need an AV AB Switch.