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.