Hardware [Old 3DS XL] Upper screen replaced – 3D not working, need help diagnosing

[Victini378]

Hi everyone, I'm repairing an Old 3DS XL for a friend. Initially, it had screen issues and made a popping sound — turned out to be a broken connector for the bottom screen backlight, which I’ve fixed.

I then proceeded to replace the upper screen, and now the 3D no longer works.

Here’s what I’ve checked so far:

• The 3D flat cable has no interruptions (tested with multimeter).
• The 3D slider changes resistance correctly and has continuity (both VCC and GND) up to the motherboard socket.
• The upper screen works fine, and the console powers on and boots normally.

Current state:

• Some components are still disconnected: microphone, camera, and infrared sensor.
• The speakers came off the upper flat cable and need to be soldered back.

I'm stuck at this point — could the missing components or speakers affect the 3D function? Or should I suspect the new screen?

Any suggestions are welcome!

 

[master801]

Some of the replacement screens now are incapable of 3D.

 

[Victini378]

Some of the replacement screens now are incapable of 3D.

Has this already happened to anyone else here on the forum? My friend and I bought screens three times and they were all broken. On the penultimate one the 3D had worked for about a minute; on this very occasion I remember noticing that one of the speakers had come off (now both). I wouldn't want their impedance (ohm) to affect something I don't know about.

 

[master801]

Has this already happened to anyone else here on the forum? My friend and I bought screens three times and they were all broken. On the penultimate one the 3D had worked for about a minute; on this very occasion I remember noticing that one of the speakers had come off (now both). I wouldn't want their impedance (ohm) to affect something I don't know about.

Sadly I don't know for sure.

I saw a few listings on AliExpress for 3DS screens (which I sadly can't find anymore) that basically said they had no 3D functionality.

Speakers don't matter in this case - they're not part of the 3D function at all.

 

[Victini378]

Sadly I don't know for sure.

I saw a few listings on AliExpress for 3DS screens (which I sadly can't find anymore) that basically said they had no 3D functionality.

Speakers don't matter in this case - they're not part of the 3D function at all.

In these aliexpress listings there was no writing about 3D. But the previous upper screen, also from aliexpress, had worked for a very short time, and just that time the speakers had come off. They are soldered into the 2 boards of the flat cable where the 3D also passes. I noticed that the 3D slider arrives first at the motherboard and then always returns in the same cable directly to the screen.