Game Cards
If your gaming console is frequently freezing, one or more of the game cards you're playing may be damaged. Game cards are extremely sensitive and should be handled and stored with care. Try different cartridges. If the console only freezes when you use a particular game card, then the card is probably damaged. If a particular game card is causing problems, check for contamination on the connector pins. If the pins are damaged, you'll have to replace the game card or you'll keep running into problems. Store your game cards in their plastic cases in a safe, dry place away from extreme temperatures.
Accessories
Nintendo provides a variety of accessories that can enhance game play. Several other companies provide unlicensed products and accessories that may or may not work with your gaming console. Most of these third-party accessories don't undergo Nintendo's testing and evaluation process, so even though they may work, they may have compatibility problems that may cause your gaming console to freeze or crash frequently. If your gaming system freezes each time you connect a particular accessory, the third-party product may be the problem. To improve your device's performance, Nintendo recommends using licensed products that contain the company's official seal. If a product doesn't carry the seal, it's likely not licensed by Nintendo.
Memory Cards and Files
Nintendo DSi allows you to transfer content such as music and photos from your computer to your gaming console. DSi is only compatible with SD cards with up to 2GB of memory and SDHC cards with up to 32GB of memory. Incompatible cards may cause your gaming console to freeze or display errors. Incompatible cards can also cause lockups. Additionally, damaged or erratic files uploaded from your computer can cause system problems. DSi only supports music in AAC format with the following file extensions: .m4a, .mp4 and .3gp. Files in other formats must be converted to AAC format using an audio conversion software before uploading them.
System Damage
If your game cards are working properly and you're using licensed products and accessories, there's a great chance your gaming console may be the problem. If you've accidentally dropped your gaming console in water, or exposed it to extreme temperatures, the internal hardware may be damaged. Contact Nintendo for troubleshooting and repair because repairing internal damage may be a difficult process beyond your expertise level. If your device is still within the warranty period, Nintendo provides a list of repair options to choose from. If the warranty has expired, you'll have to pay for servicing. Servicing fees will vary depending on the problem.