Check the CAM1 image by focusing onto a static object. The image should be crisp and sharp and there should be no visible movement. Sometimes vibrations can be transmitted through the bench, eg from the PU cooling fan.
Switch on the laser. If a loudspeaker is connected there is likely to be a lot of loud noise. This is primarily laser noise caused by the strong reflection from the static object back into the laser cavity. There should be no noise on removal of the object. Any movements, such as tapping the workplatform, should also produce a signal.