Windows 7 - Screen Display problems 7/64 bit with AMD Radeon 6450

New Dell Optiplex 790. Windows 7 64 bit/AMD Radeon 6450. I have a 5 yr old Dell E176FP1 Monitor. Using the adapter that came with the new computer so I could use the VGA plug into the AMD input.

About 2 weeks ago noticed a slight "flutter" in the screen display where the background theme colors would darken slightly then return to normal. Twoi days ago came into work and the display was not showing any whites, only a pastel type rendering as if the color hue/stauration was way off. Checked all the settings and went into AMD Catalyst Control Center to load factory defaults. No change. Tried a different monitor from about the same year, it started up fine then after 2 minutes revreted to the same problem as the other. Downloaded the new drivers/software package from AMD, uninstalled drivers, then re-intstalled. No change.

I then switched over to the standard VGA input that is right above the graphics card, re-started and the monitor displays fine.

Called Dell, checked a few things and we both decided to change out thge graphics card. Installed -same problem. Did the re-install/uninstall sequence again, no change.

Right now I am running on the standard VGA input which bypasses the AMD Radeon and uses a generic adpater which doesn;t have the greatest resoltion and such. Am at a lost as to what to do next and the only thing I can think of is a motherboard problem and I don't really want to swap that out.

Any suggestions? Was thinking of trying to hook up a TV from home that has an HDMI input?

Do any of these look familiar?

Diagnose video card problems by comparing with example corrupted screens

I suppose the description of "Tinted Screen" is the most accurate. Maybe the cable adapter that was shipped with the sytem is bad?
Still might try the HDMI input on the card and see what happens