Computer won't boot up

My computer was working fine until I put a speaker cable into the speaker jack and then the computer froze up, so I shut it off. Then when I turned it back on it wouldn't boot up at all. The led comes on and is green, but nothing appears on the monitor, there are no beep codes, the fan turns on and the cdrom light turns on but the hard drives are not making any noise. I have a HP vectra vl 800. Any ideas on what is causing the problem?

 

hmmmm Well I hate to jump off into the deep end but I would say some thing shorted out and possibly fried something if you have a non integrated sound card IE on thats pluged into a slot on the main board you can try poping open the case and removing it
also when you have the cover off check for any lose cables also with the cover of unplug the 20/24 ping Power cable from the main board and let sit for a few seconds make sure you ground your self before doing so opening up the case is nothing to be afride of unless your still under warranty all you should need is a fillips head screw driver to open it up

 

Thank you that fixed the problem