The fan used in the Kurobox is a ADDA AD0412LX-G76 which measures 40mm x 40mm x 10mm. By looking at the model number, we can extract it's information:
|AD||ADDA brushless DC fan|
|04||DC Frame size: 40mm|
|12||DC Voltage: 12VDC|
|X||Bearing Type: HYPRO bearing|
|7||Impeller number: 7 blades|
|6||Motor protective circuit & Third lead wire: by transistor with speed sensor (FG)|
|[blank]||Fan type: Standard|
Source: ADDA Model Numbering Scheme
# /bin/echo -n ']]]]' > /dev/ttyS1
# /bin/echo -n '\\\\' > /dev/ttyS1
Kurouto Shikou in Japan sells a replacement parts kit which includes a replacement fan, however, you should be able to replace it with another fan with the same physical dimensions. If you decide to go this route, you will need to make physical modifications to the wire leads from the fan.
I have two Buffalo Linkstations which also use this model of fan. Both units suffered fan failure with two months of each other. This occurred after a total period of deployment of approximately 20 months each of always on usage. Ambient temperatures never rose above 23C and the units were only lightly loaded during the whole period. At all times case temperatures remained sensibly low. The extended life claims from ADDA about their HYPRO bearing design were not evident from these two sample units.