Check Update History: any failed or problem updates just before the problem returned?
And, as before, check Reliability History/Monitor and Event Viewer for error codes, etc. that occured just before or at the times the problem returned.
Swap in known working display cables as a matter of elimination.
Turn off or otherwise disable all screen and power savers - also as a matter of elimination.
= = = =
Next:
Where are you getting drivers?
Drivers should be downloaded directly from the applicable manufacturer's website, manually installed, and configured. No third party tools or installers.
You must also be careful that the source website is truly the manufacturer's website. Just because the manufacturer's name appears in the URL does not mean that the website is actually that of the manufacturer.
As another thought: consider that there may be a loose connection somewhere. If all was fine and worked for a week and if nothing else is found then more will need to be done.
Intermittent: comes and goes with heat related expansion/contraction and/or vibrations.
Power down, unplug, open the case.
If necessary clean out dust and debris.
Verify by sight and feel that all connections, cards, RAM, jumpers and case connections are fully and firmly in place.
Use a bright flashlight to inspect for signs of damage: bare conductor showing, melted insulation, pinched or kinked wires, browned or blackened areas, swollen components, missing or loose screws, signs of moisturer or corrosion.