If it's not the fan itself, you can try a memory cache clear (non-destructive reset). If that doesn't fix it, you can master reset the display (back up user data and settings). After the reset don't reinstall the settings until you can confirm no fan alarm is present. If the fan alarm comes back after the settings are uploaded, it would be something in the settings file that is a problem. You can check the fan speed in the self-test in the Service menu (Home-Settings-Initial Setup-Service). When it enters the Service mode, press the Start Test button and the fan speed will be indicated in the left column of information that appears. Fan speed should be somewhere around 4-5000 rpm. If fan speed is lower or zero, then the fan needs to be replaced. The memory cache clear and master reset is in the System Menu as well. Click the Utility Tab and Setup button next to Master Reset Menu. Choose either Memory Cache Clear or Master Reset (Delete All Settings) depending upon what you want to do at that point.
