When I turn on computer I get no video

Question

How come when I turn on my computer, I get no video on the monitor? I checked my video card and it works fine. I recently upgraded my CPU, but my computer froze and told me to change the settings. So i decided to put back my old CPU, but now there's no video. Any suggestions? Thanks

Answer

This question was answered on December 27, 2004. Much of the information contained herein may have changed since posting.

Technology for video on VGA monitor

There has been lots of question how to do the conversion in another way: using you VGA monitor as TV. Unfortuntely there is no easy way to do it and there are no circuits in the web I know how to do that. The reason that theare are no circuit projects on the web is that an NTSC->VGA line doubler is a non-trivial project unless you are an experienced digital/ analog designer - even with the new generation of chips on the market.

I have collected here some information on this topic because this conversion stuff is so often asked in newsgroups and I have been interrested in the topic. First read my How video is shown on computer monitor technical document and check the following links for more information:

Intelligent Video Scaling - one Alternative to Line Doubling & Line Quadrupling, article includes also introduction to video conversion

Products for viewing TV picture on VGA monitor - how to view NTSC and PAL video signal in VGA monitor without using computer TV card

Ruel's PC-TV Net Page - information about computer and TV integration products

Scanline doublers - one way to show video on VGA monitor

Author

Posted by Kareem of Katharine Gibbs School - New York on December 27, 2004