IIDX Epolis upgrade with CCJ PCB

This is a little guide where I've documented the most notable parts of the Epolis upgrade I did for my IIDX cabinet, may anyone find it useful.

Feel free to DM me in Discord if you have questions: @elmiamiman

Further documentation

You can also follow this guide as it may be more comprehensive: https://docs.google.com/document/d/1i4etnZGyecHbVvoRPkY14CLfO-HF48YDg5liX45Ui2A/edit?tab=t.0#heading=h.m8ozwkt8m7wu.

Big shout out the Rhythm Game Cabs Discord server which is where I've gathered most of this info

Regarding cabinet

This was done on a beatmania IIDX Tricoro cabinet

Step 1: Swap BIO2

Swap BIO2 I/O board from CCJ for the BIO2 inside the IIDX PCB (assuming it is a CB PCB)

Regarding I/O board

CCJ BIO2 has BI2X firmware already flashed, it is not compatible for legacy IIDX, but it could be used for a 120hz upgrade

Step 2: Take important cables

Unplug CN15 and COM (CN7 in BIO2) cables from IIDX PCB, has to be plugged into the BIO2 inside the CCJ

Cables look like this:

Step 3: Get the audio card

Get yourself an Asus XONAR AE audio card and put it in any PCI slot, line signal will go into the FRONT jack port from the card

Keep in mind

You will have to cut open a hole on the PCB case at the same spot where your XONAR will be, otherwise you won't be able to plug anything into the card. How you want to cut it is totally up to you depending on what you want or need.

The resulting hole for the XONAR may look something like this:

Step 4: Place CCJ PCB inside the cab

Since the CCJ PCB is pretty large, as it cannot or it is very difficult to put inside the cabinet vertically, my recommendation is to place it horizontally, using the transformer inside and whatever you can use that is robust enough and the same height as said transformer as support, along with the wooden tray used for the IIDX PCB, which should be attached to it at the beginning (pictures shown at the end). A cleaner (and of course less crazy) solution would be building a tray or some kind of platform so it stays above the transformer.

Step 5: Readers

For the readers, the most seamless solution is to build a RS232 DB9 male connector to plug the reader serial cable and to plug into the CCJ's COM1 port, which is a JST connector

Step 5.1: Building the COM1 cable

Used parts

You can do two versions for the same solution:

1. Plugging Dupont cables following the next diagram when connecting:

Following the same color codes, the result should look something like this:

Since this only for serial data transfer, the fourth pin on the COM1 connector in the CCJ, which corresponds to +12V, goes unused, therefore the only pins needed will be, in order, TX, RX and GND.

The resulting pinout would be:

DB9 JST
RX (pin 2) TX (pin 2)
TX (pin 3) RX (pin 1)
GND (pin 5) GND (pin 3)

Be sure to keep the metal part of the Dupont side up and try to push it inside as far as you can without too much force. This just works™ but Dupont cables are pretty frail and can unplug at any time if you need to move the cabinet

2. Build a JST connector:

Following the same diagram and color codes as the first solution, you can build a JST connector for the same type as the CCJ by crimping it.
This takes a bit of extra effort but results in a more clean and resilient solution. Only materials needed are the JST plugs and terminals attached at the beginning of the section, and of course a crimper.

Result inside cab

Edit

Pub: 30 Jul 2025 16:14 UTC

Edit: 21 Dec 2025 00:06 UTC

Views: 101