Can anyone point me in the right direction for a fan that is good quality, small, already has the proper connector on the leads to plug into routerboard and work properly?
Thanks
Indeed. I am having trouble locating a suitable fan.
I don’t understand why Mikrotik designed this to use 5.5v, when 12v is much, much, much more commonly available.
Use a 12volt fan! It will work, just spin slower.
You dont need much airflow, it’s not like they put out 100watts of heat
The manual says RB333 fan connector will ouput whatever voltage you put into the RB. If u use 24v adaptor to power the RB333, then 24v will be the output of the fan connector.
Would someone with a voltage meter and a board handy test this theory 
Use a 12volt fan! It will work, just spin slower.
No, it won’t. I tried four different 12v CPU fans; one of which was brand new out of the package.
EDIT: I think I’ve put my foot in my mouth here. I dug out another fan, 12v without tach, and set manual for the port it’s on. I’m getting fan action as expected with reduced voltage. I think that the NEW fan I tried simply has a starting voltage higher than 5.5v (it has a pretty beefy motor on it). The others weren’t new and weren’t attached to anything, so it’s plausible that they are simply not functioning properly.
And yes, I moved the power pins to put them in the right order (standard fans are tach/neg/pos, RB600 pinout is tach/pos/neg).
As for a fan source, I bought some of these http://www.allelectronics.com/cgi-bin/item/CF-269/220/5VDC_45MM_COOLING_FAN_.html. I’m still experimenting, so the jury is still out on if they are good or not.
EDIT:
The tach output on these fans doesn’t seem to be what the board is expecting, when put into “Auto” mode, the system quickly fails back and forth between the fan ports; resulting in the fans running at about 1/2 RPM (the pulses are obvious). I saw the same pulsing behavior with one of the 12v fans I tried previously, but it did not fully spin.
If I set manual/aux or manual/main the attached fan spins at (presumably) full RPM. If I set auto, they pulse. I think the short answer here is: these fans aren’t really a good match; though they can be used in manual mode.
I don’t understand why Mikrotik designed this to use 5.5v, when 12v is much, much, much more commonly available.
To answer my own question - it’s probably because the on board power supply doesn’t output 12v, because they don’t need it for any components. That’s just conjecture, but it makes sense.