Hello, my 493G with 2xR52Hn is seriously overheating. Around 64C in “idle” state (just web browsing) and around 70+ when under load (few unicast HD streams).
And reboots.
Can anyone suggest where i can find power for cooler (ordinary 12v) on board?
This is from the manual:
You can connect up to four fans to the RouterBOARD RB493, but only two of them will work at a time.
JP1,JP2 are 3,3V. JP3,JP4 is the same voltage as received by the power jack. You can only use one pair of
fans (ie. JP1 + JP2 or JP3 + JP4). It is recommended to use a 12V PSU for the RB device, and JP3,JP4
headers with 12V cooling fans.
more: http://www.routerboard.com/pricelist/download_file.php?file_id=263
Yes, discovered that soon after posting 
Strange thing that i haven’t found 12v on that connectors - i found 2.2V, 3.3V, 7.7 (doesn’t really remember) and 23+.
Probably because i use 24V PoE Injector.
So i made a cludge for it 
Fan is working but i can’t manage it. Anyway, board now is pretty stable @ 50C.
Dear gentleman,
I would like to use 1 fan for cooling, I have 12V cooler and using power jack 12v
In manual I found: (https://i.mt.lv/routerboard/files/rb493-guide.pdf)
- picture of routerboard where I see 2x (6 pins) on top right side (page 3)
- cooling Fan Connectors (JP1 + JP2) for 3,3V or (JP3 + JP4) - for the same voltage on power jack connector (page 5)
- description about 3 pins (GND, power, rotation) (page 10)
On the board I found only marked pins JP1, JP2, JP3, JP4, when I checked by voltmeter I dont have right voltage.
Can somebody descript how I can connect 12v cooler with speed rotation feedback (3 pins) and mark into routeboard picture which pins on the board must use?
Many thanks for all