Why won’t my DSI turn on?

So when I press the power button on my Nintendo DSI the blue light just flickers on then off. The screen never lights or anything. I ordered a new battery and charging cable and replaced the battery and plugged it in for 24hours and it’s still the same. I took it apart to have a look at the motherboard but don’t see any obvious signs of blown capacitors or damaged resistors or anything. How could I diagnose this issue or does anyone else have any suggestions? Thank you all in advance!