My Samsung refrigerator display is reading 0F 0F

According to the Samsung support troubleshooting page:

Samsung refrigerator error codes

=== OF OF or O FF ===

Cooling Off Mode

If the display is showing OF OF, O FF, OFF OFF, or scrolling temperature bars, the refrigerator is in Cooling Off Mode, sometimes called Demo mode or Shop mode. Service is not required.

The steps to turn this mode off are specific to each model and can be found in your user manual, however the most common method is for control panels on the outside front of the refrigerator, on the left side.

1. Locate the top two buttons on the left side of the panel. On newer models, the top button on the right side of the panel is also necessary. However, we recommend trying it with only 2 buttons first as you're less likely to be in Cooling Off Mode accidentally on models which require 3 buttons.
2. Simultaneously touch and hold these buttons for 5-8 seconds, until a chime sounds. This chime will sound different than when a single button is touched.
3. Wait a few moments to confirm that the display does not return to Cooling Off Mode status again. If it does, repeat these steps until you're successful.