Go forth, update that old gray box, and pour one out for the hardware that refused to die. Have you had a catastrophic firmware fail on an SG500? Or is yours still ticking after 10 years? Drop a comment below.
If you are looking for the files, Cisco removed them from the main search. You need to navigate to Software Download > Routers > Small Business Routers > Sx500 Series . Yes, they hide the switch firmware under "Routers." Don't ask me why. sg500-28p firmware
You can flash the firmware all day long, but if your boot loader (boot code) is version 1.3.0.5 and you try to jump to firmware 1.4.11.5 , you will brick that switch faster than you can say "RMA." Go forth, update that old gray box, and