Agenda: How to build fans from old computers

Language: English

Goal of the workshop: Build a fan from several little computer fans from old computers

(you can find pictures of the result and details in the Nextcloud directory for documentation of THF 2022).


  1. Open old computer(s)
  2. unplug all the cables connected to the power supply box (grey box inside the computer, usually connected to the cable that can be plugged in the household electricity) and get the power supply box out (what’s the right word for that box?)
  3. Get the fans out of the computer, except the fan that is connected to the mainboard (because it’s not so easy and it would damage the mainboard). Most fans have one red and one black cable coming out of them. One is for 12V connection and one is for 5V connection. (which is which? and why do the fans need two different ones?) Some fans also have a whole bunch of colorful cables with a plug coming out of them. In this case, don’t cut anything off, only take it out of the computer.
  4. The power supply box already has a bunch of colorful cables with some plugs on their ends; we will use the plugs to connect the fans. Every plug has several cables going inside the plug, among them one yellow and one black next to each other.
  5. The power supply box also has one big long white plug on it. The holes in this plug have numbers. We need hole number 4 and 5. Take a small piece of cable and peel off ~1cm at each side of the cable. Then put one side of the cable into hole number 4, and the other side of the cable into hole number 5. This way they become connected. Take care that the metal disappears completely inside the holes and you cannot see any metal parts anymore, only plastic.
    (why do we connect these two holes?)

6. For every fan with a red and a black cable, do the following:

  • take one of the plugs and connect the red cable of the fan with the yellow cable of the plug. You can do this by peeling off a little (1-2cm) of the red plastic and drilling the metal pieces with each other, so you get a copper-colored end of the cable. Usually, the end of the cable is too thin for the plug of the power box cable, so you can fold the copper-colored end of the cable before putting it inside the plug (opposite the yellow cable of the plug). This way it will be double as thick as before.
  • Do the same thing with the black cable of the fan and the black cable of the plug. The plug has two different black cables. You should take the one directly next to the yellow cable.
  • Take care to put the copper-colored cable end completely inside the plug. It is dangerous to have some metal parts sticking out of the plug.

7. For every fan with a whole bunch of cables with a plug on their end:

  • Just connect the fan cable plug to one of the box cable plugs. Take care that the colors match (matching colors should be opposite of each other)

8. Ready! Now you can try the fans out. Connect the big cable of the power box to household electricity. Don’t touch any cables after you switch on the power box. When you switch on the power box, all the fans should start turning around. If one fan doesn’t do that, switch off the power box, unplug the household electricity and check again the connection of the fan’s cables.

9. When everything works, you can connect the different fans with each other (with normal strings or tape or glue…) or screw them somewhere, e.g. on a wooden stick. The fans have four holes for screws in each corner. You can also put the whole construction (with the power box) in a box with big holes, and put it or hang it somewhere.

10. Put the construction somewhere where no water can come inside the plugs.