Replacing a NAOMI Fan
If your Naomi is noisy the fans are probably old, worn and caked with dust. Find below information which might help you find replacements. You might need to cut/splice the new fan units to the old wiring/connector on your Naomi. Note, you do any of these replacements at your own risk!
The OEM fan/heatsink is a "109p4405h8016". It is a 5V and 3 wire and actually needs to be 3 wire. The additional wire is a fan speed/pulse wire. If the motherboard doesn't get the fan pulse, it won't boot.
A working replacement is the Noctua nf-a4x10-5v - make sure you get the 5V version. The pins needs to be re-arranged, the color coding is the same as the original. The noctua a little smaller, so the mounting holes don't line up, but a tiny glob of clue should hold in in place nicely.
Case fan is a Panaflo FBA06T12H, a direct replacement with equal or better specs will do just fine. The lower the dB noise level the better, the OEM fan dB is 32dB. Anything below that is better to reduce the noise levels. Note, the OEM cu.ft/min (air flow level) is around 16cu.ft/min. There are many fans which will server just fine as a replacement. The dimentions are 60x60x15mm.
The CPU fan/heatsink unit is a Sepa HFB44B05A. Again these fans have a speed/pulse wire which needs to be connected to the motherboard or it won't boot which is there to protect the board from overheating. You can get a direct replacement from https://www.buerklin.com/default.asp?event=ShowArtikel(82B130)&l=e&jump=ArtNr_82B130&ch=20737 When replacing the fan, the Sepa HFB44B05A will come with a mini-heatsink. You don't need to swap this on to the Naomi2 board, just unscrew the old fans and screw on the new fans with the adapter plate thats already on the old heatsink/fan unit. Of course you will need to cut/solder on the connectors from the old fan units to connect them to the Naomi2 motherboards.
Case fan/heatsinks are Nidec BETAV TA225DC H34587-55, 12V 0.17A. Again as with the Naomi board, a direct replacement with equal or better specs will do just fine.