Back in 2014 I wanted a build that would be seperately run from my gaming rig. I wanted a small and smooth low energy system and at the same time a build completely made of Lego. Well due to my lack of skills to make chips out of Lego at least the case is build out of it ;). Lego is the perfect material to build little computer cases as for example the I/O shield fits perfectly and also 80 mm or 120 mm have the right size. For anything else you have to be a little bit creative but I strongly recommend to build one Mini-ITX system out of Lego once in a life time.
The 1st Generation of this build was back in 2014. You can see it in the first 4 pictures. It had an AMD Athlon 5350 (2.0 GHz) built in and lacked of a proper cooler and you couldn't open the roof of the "factory". I thought the stock cooler would be enough but if you believe me or not I really had cooling problems with it. Both fans had to run on medium speeds or I encountered sudden shutdowns.
Exactly 2 years later I made an upgrade to the 2nd Generation. You see them on the last three pictures. I changed the "radiator grill" on the front, made the roof foldable for easier maintance and upgraded the APU and gave it a proper cooler. Now I can run the fans at low speed without having issues.
The name of the build "Hirnlego" is based on a part of a song from the German band Einstürzende Neubauten and can be translated to "brain lego".
Edit: The power supply is an external one like the ones used in notebooks. The mainboard has a DC jack for this. A thing more ITX boards should have.