Instructions
Go to the Nintendo repair website. Click "Nintendo DSi."
Click the problem related to your device. For example, select "Buttons not responding" if your buttons do not respond.
Select "Click Here" to obtain repair options.
Select your country.
Type your serial number into the text field and select "Get My Repair Options."
Follow the onscreen instructions depending on your repair options. Whether you have a warranty or not, you have the option to fill out a form, which includes your name and address, and this will allow you to send in the console for repair at the designated location.