FM TOWNS Tower Power Supply Assembly Guide

This new power supply runs with an AC/DC Converter and ITX Pico-PSU. The AC/DC Converter used is the Meanwell EPS-120S-12 and the Pico Psu rated for 120 watts. The Arduino Pro Micro manipulates the PS_ON line from the Pico PSU whenever the power button is pressed and TownsOS Power off is initiated. This exact concept is also attempting to be ported for a universal PSU card for desktop FM towns.

Any power supply purchased from me or Beep-san will follow these specifications.

In Summary:

-100-240VAC Compliant. No stepdown required

-Receptacle in the back meant for a monitor is going to be rated for wall-usage. This means in USA, it will be 120V. In Korea, 220V. DO NOT PLUG A JAPANESE CRT INTO THIS RECEPTABLE IF YOU ARE IN 220V COUNTRY. You have been warned

-Use of original power supply button. TownsOS Power off.

Here is the PCB

Align the Backplane connector flat to the PCB. Be sure it’s flat before soldering.

Solder the ATX connector to the motherboard. There is a white line showing the notch. Do it just like the photo.

Make sure the pin headers and Arduino Pro Micro is pointed upward like the photo. Then add solder.

Grab your supports. I used M2.5 nylon nuts, bolt and stand-offs. The holes on the PCB are M3 size for your reference. Make sure your stand-off isn’t too tall or the AC/DC converter will not be able to fit.

Get them ready.

Nuts will be on the bottom. The open stand-offs at the top. Don’t attach the screws yet.

Get your Pico PSU and cut some wires. Some are not needed. I’m using ITX Pico PSU purchased from this website. I strongly advise using the authentic one and not the fake copy. picoPSU-120 12V DC-DC ATX power supply (mini-box.com)

Cut and tin the black and white wires. They need to be long enough.

Open your dead FM Towns Power Supply. Desolder the two black and two white wires. You will be left with what you see in the photo.

If you want to use the receptable still solder two wires just like in the photo. Remember, this is voltage for your home country. If you are in Japan, it is 100V. If you are in Korea, it is 220V. If you are in USA, it is 120V

Bridge the points shown near V+ and V-.

Solder your two PICO PSU wires.

Your PSU should now look something like this. Well, don’t attach the screws in the photo. I forgot to take a photo but solder the two 2.54mm PIN HEADER to the STOCK_FAN area.

Solder your two wires in the metal shield to the ACL and ACN points.

Attach the screws securing the AC/DC converter.

Flip it over and screw the PSU back together. A few screws might not fit because it is difficult to get the fit 100%. However most of the screws should secure this fine.

Remember to plug the fan back in just like the photo.

Now enjoy your bulletproof FM Towns.

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