I have a Cisco SG500-52 switch.

On boot the Fan light comes on green, and the System light starts blinking green. No other lights show (no port lights at all).

I tried rebooting or resetting the switch using the small reset hole / button, but it doesn't respond at all. Not after 10 seconds, nor 30 seconds, nor a minute.

Any ideas? This switch did work at one time.

  • What shows on the console?
    – Ron Maupin
    Commented Oct 23, 2018 at 0:51
  • Console is interesting. It starts with this message: MAC address is not valid! MAC address is not valid, you can't use multicast or broadcast address. Enter MAC address and press ENTER( XX:XX:XX:XX:XX:XX ) : So it is asking me to enter in a MAC address? I left it blank and pressed enter just to see what would happen. Again it repeated MAC address is not valid and also Error occurred - MAC address not changed. Then it asked for Enter Hardware Revision (XX.XX.XX): Then it asked for Enter Serial Number. Seems like it is doing the initial setup that they do in the factory, maybe?
    – Daniel
    Commented Oct 24, 2018 at 15:04
  • There is a Serial Number and a MAC ID on a barcode sticker on the back of the unit. Maybe I should try entering these values? However, I have no idea what to put for Hardware Revision. There is a PID VID on the same sticker which is SG500-52-K9 V01 but I'm not sure how to translate that into the XX.XX.XX format that the Console is requesting.
    – Daniel
    Commented Oct 24, 2018 at 15:05
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
    – Ron Maupin
    Commented Dec 25, 2018 at 9:48
  • No answer. I ended up exchanging the device under warranty.
    – Daniel
    Commented Jan 3, 2019 at 2:32

1 Answer 1


The Quick Start manual suggests perhaps its performing a self-check or waiting to acquire an IP address.

Front Panel LEDs

Master—(Green) Lights steady when this switch is a stack master.

Fan—(Green) Lights steady when the cooling fan is operational, blinks green if there is a failure.

System LED—(Green) Lights steady when the switch is powered on, and flashes when booting, performing self tests, or acquiring an IP address. If the LED flashes Amber, the switch has detected a hardware failure.

  • For a normal boot process, all the port lights will flash on at some point. This was not happening. I ended up exchanging the device under warranty.
    – Daniel
    Commented Jan 3, 2019 at 2:34

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