why won't my iMac recognize my nano?

Hello fghhh,

Thank you for using Apple Support Communities.

I see that your iMac isn't recognizing your iPod nano. I connect my iPod to my iMac a lot, so I know how important it is we get this issue resolved. I have an article that I would like to share with you.

Use If iTunes doesn‘t recognize your iPhone, iPad, or iPod and see if this helps iTunes recognize your iPod, specifically, these two sections:

When iTunes on your computer doesn't recognize your connected device, follow these steps. Try again after each step:

1. Make sure that you have the latest version of iTunes that works with your computer.
2. Check that you have the latest software on your Mac or Windows PC.
3. Make sure that your device is turned on.
4. If you see a Trust this Computer alert, unlock your device and tap Trust. If you still see the alert, you might need to reset your lockdown folder.
5. Unplug all USB accessories from your computer except for your device. Try each USB port to see if one works. Then try a different Apple USB cable.
6. Restart your computer and iPhone, iPad, or iPod.
7. To see if your device needs service, try another computer. If you have the same issue again, contact Apple Support.

If you use a Mac

1. Hold down the Option key, click the Apple menu, and choose System Information or System Report.
2. Select USB from the list on the left.
3. If you see your iPhone, iPad, or iPod under USB Device Tree, uninstall third-party security software. If not, contact contact Apple Support.
   

Best Regards.