Instructions
Look at the price of the Nintendo DSi. Many resellers pushing fake Nintendo DSi consoles sell them at very low prices. As of the summer of 2011, legitimate retailers list the sales price for the device between $130 to $150; prices significantly lower are one indication that the DSi is fake.
Read the serial number; many counterfeit DSi consoles don't list the serial number properly, or have the number listed in the correct spot. The DSi serial number, which is located near the bottom-left of the touch screen, starts with "TW" and be followed by four additional digits. The DSi XL serial number, located near the bottom-left of the touch screen, begins with "WW" and is followed by four additional digits.
Call Nintendo customer service at (800) 255-3700 to verify the serial number. The representative will be able to tell you if the serial number is legitimate. Some counterfeiters print legitimate serial numbers on fake consoles. Ask the representative if this particular serial number has ever been registered. A registered serial number is an indication that the serial number was copied from a legitimate console.
Check out the packaging. Legitimate DSi consoles come wrapped in cellophane, include a user manual and warranty paperwork. Counterfeit DSi consoles will often place the DSi in bubble or plastic wrap, and do not include the necessary paperwork.