Hi and welcome to FixYa,
Initially, postback and describe the TV program source; direct cable feed, OTA (
over-the-air) or through a receiver / decoder box.
Additionally, describe how the Zenith ZRY-316 DVD/VCR Recorder is connected to the TV unit; a single coaxial patchcord or multiple RCA to RCA cables or some other means.
Offhand, a possibility to consider is that the output of the ZRY-316 to its RF OUT (Ch 3 or 4) is interfering with the TV channels received on its ANT IN. This would be more pronounced if the DVD/VCR Recorder is fed TV program from a cable decoder or DTA converter box that uses the same Ch 3 (or 4) at its RF OUT. Consider interconnecting the devices' audio & video using RCA to RCA cables.
Alternately, set the Zenith ZRY-316 to RF OUT to Ch 4 (switch at the back) and set the TV to the same.
A few things to consider:
- connections are correct, otherwise the DVD & the VCR would not display on the TV;
- very doubtful if the video head needs cleaning as VCR presumably plays the dubbed from DVD without any garble;
- since the garble is only on recording TV (RF) signals, then it could be presumed to be an RF interference that causes the "...garbled black and white image...".
Good luck and thank you for asking FixYa.