Sansui tv

Hi:
We've had this TV for about 10 years and it has worked wonderfully, with a VCR connected to it. When that VCR died, we bought a combo VCR/DVD player and connected it. Up until last Tues. I was able to program, tape and watch any VHS tape. On Wed. night I programmed it, when I came home it was still taping, went to bed and the next morning tried to watch it. It was nothing but static, with no sound. Thinking it was the VCR problem, I switched it with our other one, but discovered that both worked fine on our other TV. Then I tried the DVD part and it worked. Strange. The TV on it's own works great. And I have also changed the cable between the TV and VCR/DVD, thinking that might help.
Obviously, this is a TV problem, but what I don't get, is why the DVD part works and the VCR part doesn't. Can you give me an explanation?