I have a two year old HP S5657c desktop computer with Windows 7. The monitor will not work at all, except when first turned on. At that point it says NO SIGNAL and NO SOURCE POWER. I have reset all cables several times and have blown out all dust to no avail. I do not use it for any gaming, just everyday documents, email searches, and have about 400 photos stored. I have good ESET security on it.
Try a new Vga cable from the monitor to the back of the tower, it may be the cause.
Check both ends of the cable are tight in both ends of the connection to the back of the monitor and the Graphics out put port of the tower.
Once you have ruled these out as the cause.
You may want to take a trip into the bios section of the computer to check that the settings for the display out put video device is set right, since the board comes with an on board graphics solution this should be set in the bios as the default output device.
If the setting is different say set to Pci-e then the option needs to be set to the IGpu.
It should work then, I presume no extra graphics card is plugged into the board via a Pci-e express slot since you have indicated you do not play games on the system.