So, this is what happened. Today, I have encountered an extremely weird situation.
I am running dual monitors for my desktop, and my desktop would only display image on my monitors if I plugged in both monitors. If I only want to use one of my monitors, it would boot the system, show the login screen, and after a couple of seconds, it would just turn dark, (or blue, grey color screens, varies depends on the monitor.) But the system is clearly still running as I pressed my shift key 5 times and I do hear the beeping sound.
Does anyone can help me and explain the possible situation I am encountering? I personally think its the graphic adapter setting issues.