Monitor does not go on with XP

PC spec; OS Windows XP, Msi Geforce 9600 GT 512 MB DDR2 667 MHz Ram, Kingston 2GB Ram and another 1GB nameless.

My VLC player crashed on me and restarted my pc.
So I tried to unplug and plug back my components.
But then what happened was that my system cabinet goes on, but my monitor isn't.
Not even the ON button turns orange.
My keyboard goes on for a little while and goes off again.

What I then do was;
I used a HDMI cable from PC to Video card so I changed it with the VGA cable to see if it may be a cable problem. Still my monitor is off, keyboard goes on for a moment. No problem with my system cabinet.
I tried to connect the VGA cable to my mobo, still nothing.

How come my monitor does not turn on?

-Yes, I had windows 7 OS before, but after my issue I tried OS XP- I cannot yet change it because I was about to check my optical drive who wasn't reading any of my cd's I put in-

The monitor did get mains power. My monitor still doesn't turn on.

The cable from monitor to main power did not make proper connection.
When both ends were properly connected, my monitor did turn on. Then off again.

The second problem is my graphics card.
When it was plugged to my motherboard (i hope i state this right) I could get my monitor working again.

Thank you all for your advice.