Monitor stuck in black screen power save mode

[ImJayW]

I was surfing the web on firefox when out of nowhere the monitor goes black "Entering power save mode". Then for a split second blue screened. I can't remember if I tried to reboot it or if it turned off on its own.

Now I will turn the computer on, and the power icon on the tower lights up green as normal; but the monitor power icon stays orange/amber, when it should turn green when turning on.

Usually I would try to fix this on my own by turning the computer on in safe mode or something, but the screen remains black.

I unplugged all of the wires from the tower, put them back and same result.
When I took the monitor cable from the tower, my monitor shows a box slowly moving around the screen. It says "2 : Digital Input, self test feature check" then red, green, blue, white coloured rectangles underneith, with the monitor power icon green. Maybe this narrows down what I need to do?

I have no idea where to go from here, so any help is greatly appreciated.
I'm on a Dell Dimension E520

 

[Tmagic650]

Sounds like the on-board or discrete video card has failed

 

[ImJayW]

Sounds like the on-board or discrete video card has failed

Is there a way of fixing either of these two, or do I need to just buy a new one and hope that was the problem

 

[Tmagic650]

So are you using on-board video, or do you have a video card installed?

 

[ImJayW]

So are you using on-board video, or do you have a video card installed?

I know I sound like an ***** but I don't know. I've never had to open the tower before.
After googling, someone with a similar problem suggested taking out a RAM card, connect it all back and turn it on. Well I tried that, there was 2 or 3 beeps when I turned it on, but still nothing.

 

[Tmagic650]

Did you remove the RAM and then turn on the computer? If so, the 3 or more beeps are normal. If you re-installed the RAM and got the beeps, you need to make sure the memory is properly seated in the sockets. To find out if you are using on-board or you have a video card installed, notice where your monitor cable connects to the computer. If it connects directly to the motherboard, it is on-board video. If it connects to a card attached to a socket on the motherboard, it is a video card that can be replaced easily

 

[ImJayW]

Did you remove the RAM and then turn on the computer? If so, the 3 or more beeps are normal. If you re-installed the RAM and got the beeps, you need to make sure the memory is properly seated in the sockets. To find out if you are using on-board or you have a video card installed, notice where your monitor cable connects to the computer. If it connects directly to the motherboard, it is on-board video. If it connects to a card attached to a socket on the motherboard, it is a video card that can be replaced easily

Yes I removed the RAM and then turned the computer on.
And the monitor connects directly to the motherboard.
I hope this clears things up for a potential fix?

 

[Tmagic650]

Well, if you re-installed the RAM and still get no video, the motherboards on-board video is bad. You can still install a video card, and this might return the video normally. Of course, you may have to have a computer shop do this for you