Modding Buttons on the RG35XXSP

Last month, I replaced 15 functioning tactile switches on my new Anbernic RG35XXSP emulation handheld with ones that had lower actuation force. If you’d like to do the same, here’s a reference for what switches to use:

1. Shoulder buttons: Omron B3F-3120
2. ABXY/D-pad: Alps SKRRAAE010
3. Start/Select/Menu: Alps SKQGAFE010

These switches require about 40% less force than the originals. They are all around 100gf. The original shoulder switches were definitely C&K PTS645VM39-2 LFS (160gf). The other switches were from the same Alps series as their replacements (SKRR and SKQG). I’m guessing they were also 160gf models.

(Yes, they are also much quieter now.)

This was my first time SMD soldering. It wasn’t too bad! Don’t be afraid to try this, if you have access to the right equipment. Definitely order extra dome switches, though. To get started, look up tutorials for replacing tactile buttons and triggers for the GBA SP. The principle is the same.

To my knowledge, I’m the first modder to have replaced switches on their RG35XXSP, so I feel the need to write something about how I got here. This is not the only mod I did—for very good reasons, which I’ll describe below.

I have two RG35XXSP’s—bought in May 2024 and Dec 2024. The GBA SP was my only console as a kid, so I’m particularly nostalgic for this form factor. (Plus, each one costs less than a AAA game these days.) The RG35XXSP launched with several button issues, and it’s interesting to compare the two to see what Anbernic fixed by Dec 2024.

In summary, I’ve identified the following changes:

1. ABXY buttons have “rings”
2. L2/R2 stems are trimmed
3. Side and shoulder buttons have foam padding

Here’s a comparison of “v1” and “v2” ABXY buttons:

Anbernic added the rings after launch in response to reports of button damage. They serve to distribute the force from each press and keep the pointy stem from puncturing through the membrane and the dome switch beneath.¹

However, I noticed that the D-pad design has not changed. In time, regular use will inevitably result in the same damage to the D-pad membrane and dome switches:¹²

To mitigate this, I added 3D-printed washers to the D-pad membrane:

Dimensions of my washers, which work for both D-pad and “v1” ABXY:

1. Inner diameter: 3.15mm
2. Outer diameter: 6.50mm
3. Thickness: 0.6mm

I believe Manel Cerezo was the first to do this mod.³ These washers work just like the rings: they distribute force and prevent the stem from going in as deep. If your ABXY buttons are v1, you should do this mod for ABXY, too. If you don’t have access to a 3D-printer, consider ordering M3 nylon washers, e.g. from AliExpress.

Trimming the stem from the L2/R2 buttons is another change Anbernic made:

This makes the L2/R2 buttons go straight down when pressed, instead of pivoting. These stems are not needed for button retention, but some users who did this mod themselves reported that the buttons feel loose afterwards. It seems that Anbernic addressed that by adding foam pads.

In all, Anbernic added foam to L1/R1, L2/R2, volume, power, and reset:

Presumably, this was done to reduce rattle. I’m guessing that it also helps absorb some feedback from that “hard clickiness” as some early reviews called the button feel.⁴⁵

As far as I can tell, there are no other button-related differences between my May 2024 and Dec 2024 models. The membranes and tactile switches, when compared in isolation, look and feel identical to me.

If soldering sounds like too much, check out the “tape mod”, attributed to Aish from Aish Talks Tech.⁶ That will get you 50% of the way there for 5% of the cost and effort. The tape mod will not protect your membranes (D-pad and “v1” ABXY) from puncture, though, so you should look into buying or 3D-printing washers for them.

Lastly, people should keep potential damage in mind when buying replacement buttons. If the aftermarket buttons use the “v1” design, they could damage your membranes, which may catch you by surprise if your device was a “v2”.⁷ I hope that designers of aftermarket buttons take this opportunity to address this design flaw.

It sucks that the RG35XXSP launched with button issues, but Anbernic deserves kudos for listening to their customers and fixing some of these issues after launch. I hope they continue this trend: the D-pad design should be revised to prevent long-term damage.

(Also, consider switching all tactile switches to 100gf versions. 🙏 They feel great.)