I am currently trying to fix my HP pavilion a000 desktop. I was working fine then after turning it off i tried to start it again and it just beeps at me.

I have tried cleaning all the fans and dust of all components but its doesn't help.
I have checked the memory and cd/dvd rom but it continues to beep at me

Is this a case of getting a new tower or can it be fixed?

It could be an easy fix. Though some additional information would be needed. What pattern are the beeps (ie two long beeps, two short beeps)?

As chris.stout indicated, these beeps mean something is wrong..obviously. The advantage to the beep codes is that you do not have to have a monitor to determine what the problem is. Depending on hte patern of the beeps, you should be able to determine the issue.

I have this exact same desktop, and had this exact same problem
the way I fixed it, is to replace the graphics card.
The beep normally means that the desktop cannot detect a graphics output so it just powers down and makes one long beep