Please follow below steps to check:
1) Disconnect the power cord and connect it again.
2) Make sure the cables connected to device well.
If you connect multiple sources at the same time, use the “Source” button on the control panel to switch
3) Reset the device to default setting and try again. How to reset the unit to default setting
4) If the issue still exits after default setting, please contact your local technique support center or service center for help.  https://www.asus.com/support/CallUs
Note:
1. If those projectors with powered battery can’t be turned off at all, please press power key about 5 sec and then device will be forced to shut down directly.
2. ASUS Projector will auto-shut down if it’s overheating. Please check the working environment so that we can help you more efficiently.