Which brand of DVD-R disc did you use? What error did you get? What is your video source? Most TVs don't give video output. The tuner on the WV20V6 is an NTSC (analog) tuner. Thus you need to use a set-top box (OTA digital-to-analog converter, cable or satellite box) with the recording "channel" set to video input 1 for most channels or analog cable input to the recorder.
Verbatim DVD-R 8x, Maxell DVD-R 8X/16X and JVC DVD-R 2X have been tested and proven to work by the manufacturer. A number of DVD+R and DVD+RW or DVD-RW have been tested as well.
I've found that you have to test each batch of DVDs. Different manufacturing plants can lead to bad discs from a previously good brand.
The manual for the WV20V6 is available from Funai Corp (who manufacture the recorder for SV2000). The direct link is http://www.funai-corp.com/support/om/WV20V6.pd
f . See page 25 of the PDF for tested optical discs. No CD-Rs will work.
I hope this helps. Please add a comment with more information about your situation for additional support.