The NexStar User's Guide II - Excerpt from Chapter 11
Celestron and Dealer Support
Although most owners experience many trouble-free years of use from their telescope, if you experience problems which you cannot resolve, Celestron is naturally the focal point for further assistance. The two ways to contact them are via the telephone number for Technical Support (currently USA 310-803-5955) or by submitting a technical support request via the Support section of their website (http://www.Celestron.com). Celestron currently offers a two-year warranty on all their telescopes (including mounts, hand control and other accessories included at time of purchase). Normally they require the customer to pay for shipping back to their support facility in Torrance, California. They will pay for shipping back to you. It is best to send as little as Celestron requires, for example, only the mount and hand control if you are experiencing problems with the electronics in an SE mount.
For those who are comfortable with swapping out parts, Celestron has a limited selection of spare parts for sale on their website. The current address is:
Most astronomy equipment dealers offer a complete replacement if you receive a scope that doesn't work straight out of the box or stops working shortly after you receive it. This is always a better option than dealing with warranty repair. Some dealers also offer Celestron-approved warranty service, particularly dealers outside of the United States.