My desktop Compaq Presario has non-stop fast beeping, screen won't come up

Okay so my desktop was in storage for a few months I just got it out about 2 weeks ago I turned it on redid windows 7 an it worked perfectly for about a week. I turned it off before I went to bed and it worked great. then when I woke up turned it on it beeped repeatly. very fast beeps and they go on forever I have bought thermal compound and applyed it put it together and the beeping stopped but the screen wouldnt come on. I put the cord to my montior into my desktop too see if that was problem an no it worked . so I unplugged everything on my tower again an held the power button down for 30 seconds and plug everything back in. and the beeping came back with still a black screen. so I took everything apart again and resetted the proccesor too the cpu to make sure it was nice an tight an also took out the ram an made sure no dust was messing with it. put the ram back correctly. an turned it back on an it still beeped very fast non stopping beeps I been lookin online and I tried everything that would be wrong and nothing has worked can someone help me ?
 
Continuous beeps usually mean memory problems, but in this case I think the motherboard has failed
 
Back