Okay well I have a old jetway board, with 1 gig ram in it, Socket A processor and it will not boot upon startup, Fans start up, Hard drive won't boot but dvd drive does open. Now, I don't see anything post, Too all rights without Hard drive I should still see initial boot right? I have swapped out Harddrives, I have swapped out power supplies, and even tried my other amd board with the separate cpu. Now both of them do not working, but fans power on. Only two things I can think of, bad power supply, or graphic card not getting enough power to boot up. I tried actually 3 power supplies 1 that I know works in another computer. What could the possibilties be? I know these two are old junkers I had laying around but I just need some suggestions, Im going to swap ram, and cpu tonight and try one last power supply, but what would you think it is? Just got new graphic card because old one was having same prob. What would cause computer not to post to screen?

Incompatible RAM is a common reason for boot failure like you describe. It doesn't sound like you've checked it..

Have you tried googling the exact model name of your motherboard and the exact name of your RAM? Try to find out if they are compatible or other people have had problems with this combination.

Or if your using more than one stick of ram try using just one, then the other as you could have a bad stick. Also if it was PSU generally(and I do mean generally) you wouldn't get a screen but you would boot and post. The reason being is that your graphics card is the one thing not needed to run a computer. All other components MUST have power in order to retain the data, so if the PSU voltage drops it turns off the video card so that you can save data with keyboard commands. Incidentally try taking the video card out and see if you get any beeps then.