I have my 3 radio RB153 all configured & ready to send into the field. I opened the box today and noticed the bright blue LED flashing. Recycled power and see the same thing. The unit appears functional on the bench, so what does the flashing blue LED mean? I’m running routerOS v 2.9.39.
TIA
Does anyone even know the purpose of the blue LED on the RB153??
Well, on the 1xx series blue is the user LED and can be programmed to blink. It should be on at boot then turn off (and stay off) when ROS is loaded.
Tried to deploy system tonight. I didn’t get a good answer about the blinking Blue LED, I never programed leds before. The system when deployed seemed to reboot every 5 or 6 minutes. The flashing LED does mean something with the 2.9.39 routerOS. Had to fall back to original system while I figure this thing out.
Blue led is power led.
Do you use wireless cards on the RB153 (how many, brands) ?
Crap people, I’m color blind!
Yes, I have 3 radios: 1) senao 2511, CM9, and NMP 8602 plus
I just pulled out my second RB153 and put the 3 radios in it. I copied & restored configuration from old system. Guess what - flashing blue LED. I have no idea how to program this ‘user’ feature, It must be indicating an error somehow.
I swapped out NMP-8206 radio and put a CM9 in its place. blue led only comes on briefly for bootup. I discovered someone’s warning about these radios, and I think that’s what I saw!
http://forum.mikrotik.com/t/notice-dont-use-nmp-8602-cards-please/11338/1
Without RouterBOARD, you would still not know about this 
It’s worse getting a call from the field: “Is the orange LED on?” “No, the two orange LEDs are blinking.” 
It is not an issue with the NMP, but rather, and specifically with the lower mPCI port on the RB153. Pull out the card and the light will stop flashing. It seems that theRB153 cannot eliver the same amount of power to the third mPCI port as on the upper two.
We have had more than our usual share of problems with the 153 and have pulled all of them out.
BR,
Kristi