MSX2 FS-A1, HB-F1 & HB-F1 II Power Supply Build

The MSX2 FS-A1, HB-F1 & HB-F1 II computers use a power supply which is difficult to find or build due to the voltage it outputs and the connector it uses. If you do find one for sale online it usually commands a price equal to or more than the computer itself is worth. As described in this post I picked up a cheap MSX2 FS-A1 in Japan, and wanted to find or build an economical power supply. The following build isn’t too bad cost wise, the key thing to do is to try and minimise the cost of posting some of the components.

Doing some research, I found somebody from France on a forum who created a power supply PCB and supplied some components for a DIY power supply solution at

Note that the PCB I purchased is updated from the one pictured in the forum, as the spacing between fuses has been improved. The kit contains the PCB, diodes, fuse holders & capacitor. You need to source the transformers, plug, fuses & casing yourself. The supplier of the PCB & kit was prompt in replying, and I am very happy with the product. You will note the PCB lists the transformers needed.


The power connector for the MSX is tricky to find. It is similar to that used by the Neo Geo CD power supply, and some HP power supplies, such as the HP SDD018-1000

I found a local Australian seller with these mini IEC cables that looked compatible. After receiving the cable, I needed to remove a little rubber of the sides of the plug as it is a fraction larger than the original supply and won’t fit into the MSX with shaving some of the width off.

For the transformers I had help from a mate who could order with free shipping from a supplier.

Assembling the components on the PCB was very easy. Note that on the cables before soldering the wires in I added a rubber grommet to assist keeping the cables tight and need in the case.

For the case I decided to use a project box. The PCB has been designed for a particular case, but I took the cheap option. This fit the power supply snugly. On either side of the box, I cut a hole in the side marker out on tape for the grommets to slide into.

On the underside of the power supply double side tape was used to hold onto the base.

Where the PCB cutouts for screw mount points were, I cut some pieces of wooden dowel and used hot glue to hold in place. This will actually be enough to prevent anything moving about.


Everything fit together nicely. It all works perfectly, and looks neat in the project box. I will monitor the heat it dissipates, if needed I could cut a grill into the case for airflow.


I recommend this approach for anybody needing an MSX2 FS-A1, HB-F1 or HB-F1 II power supply unless you get lucky and find one cheaply!


  1. This is a great tutorial on building the power supply except for one item. You failed to identify which pins on the output plug get which connection. I know that the single pin is +9 V but which of the other two pis is ground and which 18V AC?

  2. I have one of these kits on the way. Thanks for the clear photos and info!

    My only question is that since I’m in the united states, do you know of similar transformers that would accept 100v-120v as opposed to 220?

    1. Glad the info helped. I am sure you can get some equivalent transformers for US voltage. Maybe the supplier of the kit can make a suggestion?

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