When using 3DTV Play, the 3D Vision USB IR Emitter will have the following light codes:
Red: This indicates that the 3D Vision Controller driver is not installed. Please download this driver from www.NVIDIA.com/drivers. Please note that this driver is not included in the GeForce graphics driver kit.
Dim Green: This indicates that the 3D Vision Controller driver is installed. The NVIDIA Control Panel > Stereoscopic 3D page should show the 3DTV Play logo. When you run applications in 3D, the light on the emitter will not change and will remain dim green.