hello i have an 532A, with 48v poe, but the unit dosen't power up when i connect the poe to the unit, i can't find the jumper setting on the manual, could somebody help, how this unit power up?

thanks

Settings are in manual here:

http://www.routerboard.com/pdf/rb500ugM.pdf

If you're lucky, the board is not blown out:

"To use standard PoE power option on this interface, JP3 and JP4 must be switched to the 1-2 position and JP5 and JP6 must be switched to the 2-3 position. The PoE input can also be switched to 12V non-standard PoE powering (switching JP3, JP4, JP5 and JP6 to the 2-3 position). CAUTION! If JP3 and JP4 are switched to the 2-3 position, and a standard (48V) PoE injector is used, the board will be irreparably broken and exchange will not be covered by the warranty."[/b]

If PoE will not work after setting the correct jumper settings, you can try to unsolder D18. If it doesn't help then the power controller (U22) is probably burnt.