Hardware 3D stopped working

[Demonbart]

Today after I got my 3DS (standard model) out of sleep mode, the 3D didn't work anymore.
If I turn the 3D slider all the way up I just see 2 images, like what you'd see when recording it through a camera, except there's no difference in how strongly the light from the screen comes across if I move the thing around (usually with 3D on when moving it around there is some variation). I've tried entering and exiting sleep mode multiple times, as well as a couple of restarts, but it doesn't seem to work.
People I've found with similar problems usually did have 3D in the home menu, but I don't have 3D anywhere at the moment.
Does anyone know what's wrong?

 

[AdityaNese]

I haven't had this problem before. Just call Nintendo support.

 

[SmileCitrus]

This problem can be caused if the cable for the parallax barrier is unplugged (the topmost one in the picture). It doesn't just pop out on its own though unless the console is dropped or suffers some kind of rough impact, so if nothing like that happened to your console it's possible there may be some other issue causing the problem.

 

[Demonbart]

It's been in my backpack a lot to rack up StreetPass hits, so I guess that could be the case, is this easily fixable or would you recommend sending it in for repairs just to be safe?
Either way thanks a lot for the tip.

 

[SmileCitrus]

It's been in my backpack a lot to rack up StreetPass hits, so I guess that could be the case, is this easily fixable or would you recommend sending it in for repairs just to be safe?
Either way thanks a lot for the tip.

If it's really caused by the cable being unplugged then yes, it's fairly easy. But I could be wrong. I have no doubt that it can be caused by that cable, but since I've only seen it come undone once or twice in consoles that weren't completely crushed, I do have doubts. I just don't want you to end up voiding your warranty and attempting a tricky repair based on nothing more than a hunch of mine.

If you do want to have a look to check the cable yourself though it's not that hard to open the top part without disassembling anything else. You just have to remove the plastic cover in front of the upper LCD so you can remove the six Phillips screws beneath. When you do this it's fairly likely that you may get some dust on the LCD though, which can be a terrible pain to get off completely when you finish and need to reapply the plastic cover.

You can get a better idea of whether or not you want to try it by looking at this iFixit guide. You would only be doing steps 23 through 27. None of the other disassembly is necessary for this.

 

[Demonbart]

Thanks a lot, I won't be voiding my warranty since my 3DS is already 3 years old, so I guess this is worth a try.