When your computer produces one long beep and followed by two consecutive short beeps at start-up and the monitor doesn't show up then automatically it has to relate with hardware problems but definitely not the memory module or RAM as what we always thought the main cause for beeping sounds, rather, it has also something to do with the Video Card problem based on the beep codes according to pcguide.com.
But before I make known about this process, I really couldn't understand why one of the computer in my workplace in which produces such sound above was not working since the memory is tested to be working and Video Card is just two months old from the time it was bought. That's why I suspect that the motherboard might had damage or worn-out already because it's quite old. I even attempted fixing it by replacing the motherboard and the central processing unit or CPU with the identical spare that we had, however, there were no changes happened and the effects remains to be the same. So I dumped it for almost week.
Until I replace the Video Card, that computer that I was referring for is now working normally and smoothly like a brand-new unit. Then, it was another successful computer repair for me. So thank you so much for reading this entry and please don't forget sharing your comments and reactions.