Follow the steps below to troubleshoot this issue.
IMPORTANT: This can be caused by attempting to turn the projector off and then quickly turning it back on. After turning off, the projector should not be turned back on for at least 2 minutes.
- Ensure the lamp cover is securely closed.
- Ensure the air filter is securely closed.
If the issue is still unresolved, service may be required.  Go to Product Repair.