UHD + USRP2 + WBX doubt

I am using the WBX daughterboard with USRP2 interfaced using the UHD
Driver.

The LED boot sequence is as follows

  1. F turns on
  2. E, C, A turn on and then blink and turn off
  3. D turns on

is the above sequence correct? (B never turns on)

also when I run uhd_fft.py, led C turns ON. is it normal or shud i be
worried?