Forum: GNU Radio Why is my USRP N210 front panel LED E light blinking rapidly all the time?

Hello,

As a new user I have just made the uhd_fft.py to display something. I 
use
the LFRX daughter board for initial testing. I have a concern with the
front panel LED E light. While the uhd_fft.py is working, both the LED C
and E lights are on solidly which is expected. When shutting off the
uhd_fft.py, the two lights went off also. But the LED E light starts to
first slowly blink and then to pick up speed in blinking. The E light 
being
the ref lock, I am guessing the rx board doesn't like not having a ref? 
It
got really annoying watching the fast blinking light. I fear that this
might not be good for the overall health of the system. The only to cure
this seem to be power cycle, which is not preferred. What should I do to
prevent this or to ensure that everything is working correctly and there 
is
no system complaints?

Thanks,

LD Zhang

It's fine, ignore it. The LED is reflecting the fact that the internal
oscillator is unlocked from the reference, which is normal when the 
device
isn't being used. When you initialize it again next time, it'll lock up.

--n