Tact switch mod for the Game Boy Advance (clicky buttons like the GBA SP but for regular GBA).
The goal behind this mod is to allow AGB consoles to be repaired (or just converted) from regular membrane buttons over to the tact switches that GBA SP consoles use.
Contact pads are designed to accomodate a wide variety of buttons.
I've uploaded both boards to OSHPark: DPad, A and B. Best to order them as flex PCBs to have them as thin as possible.
Gerbers are available in gerbers directory.
Soldering PCBs to GBA main board is pretty straightforward: line up holes with corresponding test pads and solder them down.
When soldering buttons, try to center them as best as you can. On DPad this can make big difference in how they will feel during use.
Next steps depend on the height of the buttons you're using.
For example, ALPS SKRRAAE010 sourced from mouser or lcsc.
Depending on circumstances, you might need to add small cardboard pieces onto each conductive pad on the membranes (pads on aftermarket membranes can be quite soft and spongy, which doesn't feel great when you're trying to press a tactile switch). You will probably also need to add cardboard pieces in the middle of DPad board in order to lift the DPad a bit and prevent it from pressing too many buttons at once. See the video for more details.
A better option is to 3D print the adapter. Print slow and with supports and snap the adapter into the DPAD. Install with no membrane. Shimming the middle support post of the DPAD may be necessary to prevent hitting all four buttons simultaneously. Too low and you will hit all buttons at the same time, too high and you will not be able to hit any buttons.
I've tried the following buttons, in the order of preference:
- ALPSALPINE SKQGABE010 - ~160gf, 0.25mm travel, 500k cycles (lcsc)
- XKB Connectivity TS-1187A-B-B-B - 160gf, 0.2mm travel (lcsc)
- Quite a bit louder than the above
- Diptronics TBEG-W-Q-T/R - 200gf, 0.12mm travel, 200k cycles (lcsc)
- Too fiddly to solder
- XKB Connectivity TS-1187A-C-A-B - 260gf, 0.2mm travel (lcsc)
- Turned out to be a bit too stiff
To make them work you'll need to trim about 1mm from the rubber membranes. On the aftermarket membranes I have, that amounted to just gently cutting off conductive pads with a knife, flush to the rest of the membrane.
Additionally, you'll need to stick something about 0.6mm thick in the middle of DPad PCB in order to prevent DPad from activating too many buttons at once. Adhesive pad that came with the IPS display worked pretty well in my case.
- Test pad holes drill diameter reduced to 1mm
- All test pads now have cutouts for easier soldering
- TP6 pad changed to remove overlap with nearby RESET pad on the main board
- GND pad on DPad board moved a bit to the left, reducing the distance to shoulder button