If your Nintendo DS system activates Sleep Mode during gameplay, follow the advice below.
When you close your Nintendo DS system, a magnetic switch is activated near the Start and Select buttons that causes the system to go into Sleep Mode.
Make sure there are no magnets (e.g. from speaker cabinets, fridges, etc.) in the surrounding area while you are playing your Nintendo DS, as this may interfere with the system, causing it to go into Sleep Mode.
If your system is still switching to Sleep Mode it’s likely it will need to be repaired.
Book your Nintendo DS in for inspection by the Nintendo Customer Support Team.