how can I fix my 17inch DGM momitor?

Let see if I read you correctly...

The initial message appears whenever there is no signal, like the video cable is disconnected. That kind of message can also get displayed when the computer is off while the monitor is on.
Then, apparently, the built-in screen saver of the monitor kicks in.
You then see some flashing of the Windows' own screen saver.

It looks like you have some faulty connection somewhere, then, as the system heats up, the thermal dilatation allows a somewhat good connection.
Done with the diagnostic.

Make sure that the cable is solidly connected to both the monitor and the computer.

Try using another video cable, your actual cable may be damaged.

Look at the monitor video connectors. Any loose connector or any cracking around those?
If the plastic around the connector is cracked, you can probably glue it using some super glue or plastic cement.

If the connectors are loose, there should be some screws that you should gently tighten. Don't over tighten as that can cause cracking or breackage. You may need to open the monitor's case to do that.
If the connector got loose, some of it's welds are probably cracked. You should use a small welding iron/pen to biefly melt the welds and repair any cracking.

If you still have the same problem:
Make sure that the video card in the computer is securely inserted. You need to turn the computer OFF and disconnect it before processing.

Open the case. Touch a metallic part to discharge any static electricity.
Remove the screw securing the video card in place.
Remove the card and immediately put it back in in exactly the same location and way.
Press it frimly down into it's socket.
Tighten back the screw, close the case, reconnect and power up.

Electro
January 2012