I believe you come here casue you have seen my video about add USB-C Audio & charging Port for your Gameboy advance SP:

 

 

Yes, it’s currently best way to update your SP, if you still like to play it on-go without taking some more specific SP charger or audio-out toggle. And i’m glad to share with you some tips about how to mod:

1.  Buy a proper 24pin Usb-C port, not any port can realize the audio function.  I have used this one below, you may purchase it from amazon or aliexpress. 
2. when you remove the original SP charging port, take care not to solder off the pads. but it’s really hard if you have a soldering iron^^^ but don’t worry, you can still wire from other pads on mother board instead just like what i have done. I have share my solder schematic at end of the post.
3. fastening the port with SP mother board. There will be lots of plug in/out with the new port, so it must be installed steady there, and here is my method: solder 2 90 degree  folded sticks to the port, and then stick into the original board’s through holes for original port.
4. 
5. cover the hole at shell top. the new usb-C port is much smaller than original ugly big port, so a big hole is left at shell top. if not covering it, all internal PCB is exposed^^ and I have designed a 3D print part to cover it, and it fits in perfectly. more important the part also help to fasten the port. You can download the 3D model file from links at end
6. 

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And finally share with you the detail soldering schematics and the 3D print part.

if your really appreciate my sharing and want to support me, you may click the picture and buy me a coffee:)

 

and get the files by click links below:

google drive folder link

 

Byebye all retro boys and girls.

many thanks to 666Gothicgirl , who has first workout the MOD.