Hardware 3D Effect not recognized after Mainboard Swap

[IaguCool]

Hey guys, I have a New 3DS XL (2015), just need your advice about something. After messing up the Home button ZIF connector, I installed a new mainboard.
Everything works except the 3D Effect, which isn't recognized and won't let me get past the initial 3D Sensor Check even though I slide the 3D slider back and forth.

I thought it might be a defective mainboard, but no. I installed my original mainboard and the 3D Effect stopped working there either. So I'm suspecting that one of the upper screen ribbon cables was messed up because of the repeating bending.

Do you know which part I should replace? There are only 3 ribbons involved: The top black ribbon for the camera modules, and 2 underneath the main board: the main screen ribbon cable, and the other ribbon cable that connects to the sliders and the speakers (and has some extra 2 tiny ribbons from the screen, which could be related to 3D as well, so that ribbon cable could be the culprit too).

 

[TariqSoftDev]

As my belief since the 3DS screen uses (Lol forgot the 3D method) buy a new Top screen , I think you've broke one of the flexs, carefully examine all of it , also if you did alot of bending you may have broke one of the copper traces on the flex cable

 

[rip-it-up]

Are you sure you didnt damage the slider when you reassembled. Ive had this in the past and ive just resoldered a new one on the cable rather than dismantle the 3ds again to change the flex.

I have never worked on the new 3ds just regular and xl

 

[IaguCool]

Thanks for your answers guys. Yeah I'm sure it's not the slider itself because I didn't disassemble the upper part at all. For now I ordered a new speakers/sliders ribbon, I suspect it might be the issue, and it's the cheaper option as well so I'll just go with it first. After disassembling the top part for examination, I noticed a scratch on the speakers/sliders ribbon, and the volume slider stopped responsing as well, so I need that ribbon cable anyway, it might be what went wrong.

I'll let you know how the repair goes. I hope you have more ideas in the meantime, I just couldn't find any guide about what each ZIF connector is responsible for.

 

[TariqSoftDev]

Idea!!! the ZIF connector thats under the board on the left has something to do with the top display showing images as I remember once i forgot to connect this and the back light came on without image

 

[IaguCool]

Idea!!! the ZIF connector thats under the board on the left has something to do with the top display showing images as I remember once i forgot to connect this and the back light came on without image

Sure, that's where the top screen's main ribbon cable connects, without it you won't get any image on the upper screen. However, you do see backlight, and that's where the other ZIF connector comes into play. There are those 2 tiny ribbon cables that come out of the screen into the speakers/sliders ribbon. The console will work when the larger one is disconnected but won't work if the smaller one is disconnected. One of them must be responsible for backlight control, the other may be responsible for the 3D effect. (If anybody knows any better, please share with us)

 

[IaguCool]

I can confirm that the issue was the Speakers/Sliders ribbon cable. After swapping it with a new one I ordered on AliExpress, the 3D Effect is working perfectly.