PCI LEDs?

Hi,

I have about seven RB153s with various setups. One of these RBs has a blue PCI LED illuminated all the time, this is the LED beside the Green power LED. This PCI slot has a WIFI card installed, when I remove the card the LED is no longer illuminated. Does anyone know where i can find out that this means? Is there somewhere in the router config that I can see what is causing this?

Thanks for your help.
Mike

Was this a stupid question? I’m still confused, I’ve read the manual over and over and cannot find any answer. Can anyone have a guess at what these LEDs indicate?

Regards
Mike