Amiga 2000 Fan

Amiga 2000 Power Supply Fan Mod

Today we are going through the simple process of modding an Amiga 2000 power supply (PSU) with a new, much quieter fan. I have always been a fan of Noctua fans, so my goal with this endeavour was to see what it would take to get one installed in my Amiga.

While there were a number of different power supplies that came with the A2000 systems, I’m sure my particular type isn’t the only one that’s distractingly loud. Let’s fix that.

Liton PA-4201-5A 200 Watt PSU

Here’s the particular model of PSU I have in my system. If you’ve got the same in yours, you should be able to follow this guide without issue. If you’ve got something else, I still hope this helps you in some way.

The Parts

All we need for parts is the replacement fan. I decided to go with the cadillac of fans, a Noctua NF-A8 ULN, which is the Ultra Low Noise variety of their popular NF-A8 line of 80mm fans.

https://noctua.at/en/products/fan/nf-a8-uln

They also offer most of their fan models in a PWM 4-pin variety, but you’ll want to stay away from those, as PWM fans were not popularized until the last decade. They will have a 4th pin for the input for pulse width modulation, that we don’t need.

What's in the box
Extension, ULN adapter, Molex Adapter, Screws, and Silent Mounts

Step 1: Open up your Amiga 2000, and its PSU

Remove the cover on the case of the Amiga by removing the 4 screws along the bottom of the sides, 2 on each side. You’ll also have to remove the one screw in the middle-top, close to the fan.

back-screwNext, remove the 6 screws that hold the top of the PSU itself on, which will gain you access to the internals of the PSU.

psu-screws

Step 2: Remove the old fan

Step 1Remove the old fan from your Amiga. It’ll be straight forward to remove, with just the 4 screws on the back, and the cable plugs that into the PSU board with a typical 3-pin fan header. Be careful not to touch anything in the PSU, as the large capacitors in there are capable of holding quite a charge, and the last thing you want to be doing it shorting them out and giving yourself a shock. Don’t go tossing out the included metal grille, as we can use that when we install the noctua for that nice factory look.

Step 3: Prepare the new fan for install

For my model of PSU, the pinout on the 3-pin header did not match the pinout of the new Noctua fan, so some modification was necessary. Luckily, this is a very simple swap, as the wires in the Noctua are the same as in the old fan, they’re just in a different order.

The pins in the header are held in by little spring-pins that you can press down through the slots for each wire, and gently pull them out.

Fan Header Spring Pins
Fan Header Spring Pins

You’ll need a small knife or pin of some sort to release the wires  on the 3-pin header on the Noctua fan, and re-arrange them as the photos below show.

Noctua pins - before
Pin Layout: BEFORE
Noctua pins - after
Pin Layout: AFTER

Step 4: Drill out the PSU to fit the new screws

When I first went to use the fan screws that came with the Noctua, I noticed that they did not fit into the holes in the PSU, due the stock fan using a non-standard screw size that’s much smaller. I drilled out the holes on my PSU to 3/16″ and it worked out to a nice tight fit. The standard fan screw size is 7/32″, so you can drill for that or 5.5mm, and it will work out fine.

Drill Holes

Step 5: Installation of the new fan

You probably noticed a few things in the box of the new fan. One of the accessories is a Ultra Low Noise Adapter, and it’s why this fan is called the ULN model.

Noctua ULN
Ultra-Low Noise Adapter

It’s essentially an in-line resistor that will take your fan from the stock 1400 RPM (which is already quiet), down to a paltry 1100 RPM which will likely be inaudible in a normal setting. I opted to install it, as I wanted my setup to be as noise-free as possible. I haven’t had any issue at all with the new fan running at such low speeds, but my setup is also in the basement where it’s fairly cool most of the time. You can determine what configuration you’d like to go with depending on your setup. If you’re not interested in the ULN adapter, you can order the fan without it to save a couple bucks.

Install the fan in the same way that you removed the old one, making sure that the direction of flow of the new fan is facing outwards to the back of the PSU. You should also install the stock metal grille on the back.

Route the cable in a way that makes you happy, and plug it into the PSU. Test it out to make sure you’ve got everything right, then button everything back up.

Cable routing
Upside down fan

That’s it! Go play some games!

Below are two videos I took to showcase just how quiet this fan is. It’s really changed the experience of gaming on this machine for me, as you cannot even tell it’s running if the monitor isn’t on. It’s fantastic!

Noise comparison

Thanks for reading, and happy modding!

Posted by

Raskulous is an avid gamer, retro gamer, and computer enthusiast. He also spends portions of his free time doing electronics service and repair, and console modifications.

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