I have rb532 and 18 DCV power adapter but I can't start system. I've changed jumper on board for both position ( 12V and 48V ) but rb still doesn't work. If someone have the same problem and has solved problem i'll be very grateful.
Make sure power adapter is not broken (try it with another board),
switch jumpers correctly for 18V and Pext (not PoE).
If board or power supply will not work (switching on power supply, leds are not flashing), then contact the company who sold the equipment.