Check that the device is switched on by pressing silver button on side.
Try switching the eye piece arm to your non-dominant eye and see if any image available. If present return to dominant eye and continue to adjust eyepiece
Check the Microsoft Teams app microphone does not have a line across it and is muted – if microphone is off say “MIC ON“
Check that the eyepiece is not blocking the camera site
When setting up the HMT, look ahead at an object / person. Then without moving your head look down into the eye piece and see what your camera is sharing. If this is not what you were looking at take one hand and hold the body of the HMT (opposite side to the camera) to ensure that the HMT does not move while you adjust the position of the camera with your other hand.
Once you see the original object / person that you were looking at clearly displayed within the eye piece screen then you have set up your HMT correctly for use. The caller will now be shown, through the camera, what you are looking at.