tv suddenly won't show vcr image or antenna channels

I received this large Toshiba for free several years ago, so I don't know the model. It has worked fine for a while in this setup: DVD player hooked up to S-video, VCR hooked up through RF cables from antenna, to tv, and the yellow RCA cable, as well as audio. (DVD player audio just went to an old stereo receiver and speakers.) Suddenly, one day, there was a small pop and the screen just showed noise. I can still watch dvd's, but the tv won't show the vcr tapes, or regular channels via antenna. Was it ok to hook up two things at once to the tv, or was i supposed to get a switcher? Did this break something? Is it easily fixable? Thanks for any help.