Sorry the power settings didn't help you. Have you changed/upgraded any hardware recently? Aside from a possible graphics chip melt down, there is a possibility of the monitor being bad too. I recently had one go bad after only 18 months.
Is your graphics built-in the motherboard?
EDIT: I checked the spec, yes it is. There is a graphics driver dated 7/15/2010, V184.108.40.2069, check to see if yours is up to date.
New BIOS too 12/8/2010, P5G41T-M LX 0604. There is a beta BIOS listed, but I never use a beta BIOS and don't generally recommend updating unless there is a problem, which you do have. P5G41T-M LX Downloads