Blue light turns on then off. No popping. No screens. No boot.

Hi guys! I made the silly mistake of buying a broken N3ds XL on eBay thinking I could fix it. Here is what I've discovered: all the cables are good and correctly hooked up inside. Pushing the power button makes the blue light turn on and then off. I never get any boot, nothing shows not he screen, and there is no noise or popping from the speakers. I took it apart and checked all the cables, took out the micro SD card and put it back in, etc. I cannot figure this out. Any suggestions would be appreciated.