Display problem

Assuming this is pci, did you try another slot?

Assuming its agp, sounds like the slot might be shot?

Did you take the monitor with the cable to another pc and see if it works? If it worked then I'd say you have a motherboard that is either warranty work or trash...

Good luck..

Troubleshoot the problem by first checking the cables to the video card and monitor is getting good connection

Check for updated video drivers also check the refresh mode by booting into safe mode and reducing the refresh rate and resolution

Check the memory modules to make sure they have not crept out the slot by checking inside the case

If the monitor can display the message to please check Cable chances are that the problem is before the monitor but trying it on another PC will tell you. Check the cable and sockets for bent or missing pins. Just plugging the cable into a video card that is sitting on the desk will make the no signal message turn off if the cables are good.

I'm going to go with either one of two choices on this. either your slot (AGP, PCI) is bad since your replaced the vid card. Or your monitor cable is bad. if in case of the monitor cable if its a screw in on the monitor, just go replace it. If not it would probably be just as cheap to buy a new monitor then to try and have it repaired due to the risk factor in dealing with monitor repairs,