Chosen Solution
I recently did a repair of the bottom screen, while doing so I probably damaged the digitizer since the touch screen wasn’t working anymore, so I bought a new digitizer and I replace it with the old one, but after this repair once I turned on the console the blue LED turned on for a few seconds, then when the backlight turned on the entire 3DS shuts off with a boop sound, I tried reseating every flat cable, but to no avail. Please Help Me! (Sorry for the repost but I posted on the wrong product)
Do you happen to have a magnet under it? If not, i would check if the ribbon cables are all connected right, I remember something like this happen with the ds, and it was because the screen ribbon cable wasn’t in all the way