The overhead (transparency) projectors in our classrooms contain two lamps. If the primary lamp burns out, you can switch to the alternate lamp by following these instructions:

1. Turn off the power to the projector.
2. Locate the lamp selection lever on the side or rear of the unit.
3. Move the lever from "Main" to "Reserve", or vice versa. The selection lever must be pushed all the way to the Main or Reserve selection. If the selection lever is not fully engaged, the lamp will not turn on.
4. Check the power connections for the projector and mobile cart, then turn the power switch ON. The alternate lamp should now function properly.

If this still does not resolve the issue, both lamps may need to be replaced.