Screen not responding

[EatingBeef]

I was cleaning my computer from dust the other day and after I finished I tried to turn it. Everything went quite well except the fact that the screen didn't show any image. So I thought that maybe the there is a problem with my screen so I brought another screen and plugged it to my computer ,but it still didn't show any images and when I turned it on it said "no signal" and turned off again. I checked if I maybe unplugged any cables while cleaning my computer but everything seems connected. Do you have any suggestions what the problem might be?

 

[EatingBeef]

By the way I am not a native speaker so I am sorry if I spelled anything wrong

 

[MindoverMaster]

Try reseating your graphic card, if you have one. Might want to try it with one stick of RAM. See if that works.

 

[EatingBeef]

Well I think that worked because when I turned on the computer the screen responded ,but now I have a greater problem. When I saw that things are getting better I asked myself "why don't you clean your computers case and components?" so I disassembled my computer in order to clean it. After I connected everything back I turned on my computer and it started to beep and after a few beeps it turned off. Now I am really confused because I am sure that I connected everything to its place. By the way thank you MindoverMaster for helping me with the screen.

 

[MindoverMaster]

What is the beep code?

Computer POST and beep codes