Troubleshooting if the Mi Smart Projector cannot be powered off via the remote control, please refer to the following steps:
1. Make sure the remote's batteries are properly inserted and have enough power. Weak batteries can cause issues;
2. Take out the batteries, hold any button for 5 seconds to discharge remaining power, then put the batteries back in. This can reset the remote and fix problems;
3. Try other functions on the remote to check if it's working. If not, try new batteries or a different remote;
4. Ensure nothing blocks the path between the remote and the projector. The remote needs a clear view to work;
5. If the remote still doesn't work, try using the projector's buttons to power it off. If they work, the remote might be faulty;
6. Check the projector's settings menu to ensure there are no settings preventing the remote from functioning properly. Resetting the projector to default settings may also help;
7. If the issue persists, contact your local after-sales for further assistance regarding this issue.