The quivering has increased but comes in spurts. We've disconnected things like the answering machine and have tried plugging the monitor into an outlet with no other appliance.

My ONLY issue is the quiver. I ran all the 'tests' I know of and all came back fine. The cords appear tight.

We did take the cover off the PC and vac it when remodeling the room. Could something have come slightly loose tho we thought we were so very careful?

Would you guess a bad video card instead with only the quiver problem?