That's really frustrating, I've had similar issues with my own laptop before. The fact that the flickering happens when you adjust the hinge or wake the device from sleep suggests that it's likely a connection issue, so I'd say a loose EDP cable connection is a pretty good guess. It's possible that the cable is just not seated properly or has become loose over time, which would cause the screen to flicker. Before assuming the integrated graphics chip is failing, I'd try to check the EDP cable connection and see if tightening or reseating it resolves the issue, it's worth a shot before considering more serious hardware problems.
