why are electronics so difficult?

I spent a lot of money on speakers for my year-old stereo. I needed to replace the cheap ones I had, plus take advantage of my surround reciever. Since I was upgrading the speakers, I figured I'd better get some decent cables to transmit the sound from the CD player and DVD player. Once I got everything replaced, I couildn't get any video from the DVD player. It comes through fine from the VCR, but not the DVD. I tried everything I could think of, and even discovered a few new tricks with the reciever, but nothing helped. Then I put the old cables back they way they were, but I still get no video from the DVD player. What's up with that? It makes me wonder if something's wrong with the DVD player.