1. Q: There is a picture but no sound when the video is playing, why?
A: Is the cable connected to the projector loose? Please also check whether the machine is muted. Some devices do not support Dolby. Contact customer service if it's a speaker problem.
2. Q: The screen flickers when the video is playing?
A: This may be caused by an unsupported refresh rate (for example, 120hz). The projector only supports 60Hz. It also may be caused by external equipment interference. Contact customer service if it is an overall projector problem.