By watching it over and over again I noticed the bubbles coming from the center of the fan. I also noticed that just one seems to be working. So can it be that the fans burned due to the liquid resistance?
The moral of the story: Never submerge air blowing fans into liquids lol.
As others have said, you need either a "solid state" (chip) fan simulator, or a firmware that lets you start without fans. Some lazy people just place the fans outside the liquid, extending the wires if needed. Too bad you already burnt yours...