Old 3DS XL blue light turns on and off after a couple of seconds, nothing else happens

[HexFY]

Well, that sounds like something i won't be able to do

 

[CoolMe]

GodMode9 and Luma3DS settings as well as safe mode work fine.

Even with a faulty or non-functioning camera?
So from this it's some other hardware component that's causing the issue for OP..

Disconnecting the bad camera makes the system boot up normally (obviously without the super stable 3D as it needs the camera for head tracking).

Old3DS (XL) don't have that problem. In neither model a disconnected camera will prevent booting.

Interesting.. Thanks for the info!

Usually the abrupt shutoff is caused by torn cables to the upper screen assembly (might be very small damage). When they start tearing they must be replaced. Replacement of upper LCD and loudspeaker cable is needed (both, since they are both worn). Loudspeakers are soldered to the cable, so make your soldering equipment ready. Not a hard soldering job. Way harder is routing the new cables through the hinge without breaking them.

OP sorta jumped the gun with opening the 3DS and unplugging the inside components before exhausting his options with the software side. But that's done now..
It could be the ribbon cables as you said, since it's necessary for him to disassemble the upper part of the 3DS in order to unplug the cameras..
Though from what've seen (speaking from experience), a faulty sd card reader can give a slight blue light blink and with no speaker popping sound. And this is a possibility as well, that's why i suggested this to him first before anything else..
Not sure if a faulty or non-existing WiFi board can exhibit the same behavior or not, but it's worth looking into if changing the sd card reader couldn't fix it.
From what i know the system will not into either the home menu or Luma3DS /GodMode9 without an sd card reader, for N3DSXL's, i assume it's same for old 3DS's?

 

[HexFY]

OP sorta jumped the gun with opening the 3DS and unplugging the inside components before exhausting his options with the software side. But that's done now..

I'm pretty sure i spent 2 or 3 days trying every software solution that was suggested to me before opening it for the first time tho

Also, if it was a faulty SD Card reader, would it still be able to create the luma folder inside the SD Card? That's the thing i'm most intrigued about

 

[CoolMe]

Also, if it was a faulty SD Card reader, would it still be able to create the luma folder inside the SD Card?

What do you mean by "create the Luma folder"? Are you talking about the Boot.firm file or the payloads? In either case it can't create either if they're not present on the sd card..

 

[HexFY]

As i mentioned before:

Since i can now post links, here's a screenshot of the luma folder i mentioned after trying to boot the 3ds with boot.firm and boot.3dsx only.

The folder is created after i try to boot the 3ds with the boot files

 

[KleinesSinchen]

As i mentioned before:

The folder is created after i try to boot the 3ds with the boot files

Wild guess: You are missing config.bin (config.ini for latest Luma3DS). Luma tries to create it after creating the SD:/luma folder. Since Luma settings also turn on the screen backlights, the console shuts off.

Provide a file SD:/luma/config.bin (config.ini), the console will try to boot (blue light stays on longer) and turn off once the normal operating system wants to initialize backlight.

 

[HexFY]

Wild guess: You are missing config.bin (config.ini for latest Luma3DS). Luma tries to create it after creating the SD:/luma folder. Since Luma settings also turn on the screen backlights, the console shuts off.

Provide a file SD:/luma/config.bin (config.ini), the console will try to boot (blue light stays on longer) and turn off once the normal operating system wants to initialize backlight.

This is interesting, i tried creating the config.bin (i'm using the luma version i previously had) as a blank file and of course nothing changed. But, when i used this website to create the file, the blue light stayed on for much longer! Except when i try to boot holding SELECT.
Since i don't know what the configurations on the website do, i used the default ones, but this gives me hope

EDIT: tried putting the godmode and the rest of the files from the guide in the SD Card, now the speakers make a pop sound when it turns off.. god damnit.

 

[IC_]

This is interesting, i tried creating the config.bin (i'm using the luma version i previously had) as a blank file and of course nothing changed. But, when i used this website to create the file, the blue light stayed on for much longer! Except when i try to boot holding SELECT.
Since i don't know what the configurations on the website do, i used the default ones, but this gives me hope

EDIT: tried putting the godmode and the rest of the files from the guide in the SD Card, now the speakers make a pop sound when it turns off.. god damnit.

The issue is most likely exactly what Sinchen described in that case, the cables going to the top part of the 3DS are not making a proper connection. While you could still try carefully reconnecting those cables, continuing to push them in while locking the connector to be sure, and also cleaning the connectors on both ends with alcohol, at this point it's unfortunately more likely that the issue lies deeper in those cables, being either that they have been damaged or are simply worn out from age and use.

 

[HexFY]

I tried re-seating the cables on the board again, just to be sure, but the same thing still happens. If the issue is with the cables themselves then that's very unfortunate indeed