IMPORTANT: This article applies only to specific products and/or operating systems. Check Applicable Products and Categories for details.
If possible, move your eye a little closer to the viewfinder. The viewfinder has a proximity sensor. If you are not close enough to the viewfinder it will not turn on.
This also may happen if the FINDER/LCD Setting option in the menu is set to LCD Monitor. Instead, you may want to change this option to Viewfinder or Auto.
NOTE: If model-specific information is required to complete any of the steps in this solution, refer to the operating instructions supplied with the product. Manuals are posted on your model support page.