My laptop is not powering on

Unresponsive shoulder buttons on a DSi are usually caused by dust or oxidation inside the button contacts. You can often fix this without disassembly. First, turn off your DSi, then spray a small amount of compressed air or isopropyl alcohol (using a cotton swab or syringe) around the L and R buttons. Press the buttons repeatedly while doing this to loosen debris. Let it dry completely before powering on. If that doesn’t help, the internal switch may be worn out, requiring you to open the DSi and clean or replace the micro-switches—but only do this if you’re comfortable with delicate repairs.