Why is the cursor difficult to press left and down?

"Hi,

The contacts for the left and down cursor may be dirty. Being an un-used device they shouldn't be worn out.

Here is a link to the ifixit repair guide for the device.

Here is an image taken from the repair guide. I have highlighted which contacts need to be cleaned, both on the board and on the rubber pad. (The rubber pad contacts have a conductive coating which bridges across the contacts on the board, when the button is pressed down completing the electrical circuit)

Use a Q-Tip moistened with IPA 90%+ (Isopropyl Alcohol - available at most pharmacies - do not use 'rubbing alcohol' as it is not as effective)

(click on image to enlarge for better viewing)

Take note of the caution issued at Step 9 in the ifixit teardown instructions

Alternatively since you stated that you bought an un-used device, did it come with a warranty at all?

If so follow up on getting a warranty repair or replacement as by trying to fix it yourself as shown above, will void any warranty.

Hopefully this is of some help."