I have this Cisco SG300-28 Switch that I bought from an auction a year ago, was working well until it suddenly stopped working for no apparent reason few weeks ago. Removed all the network cables and brought it upstairs. When I plug the power cable with everything else disconnected, all the port lights blink twice and then the System LED starts blinking rapidly around 4 times per second roughly. If I plug in a network cable, there's no light/activity at the switch or pc end, and ipconfig command on my PC says media disconnected. Tried resetting the switch but holding down the reset button for even a full minute doesn't make any difference. I opened it and grossly everything looks fine. Need some help to get it working again. I have no prior experience with cisco or switches.

https://preview.redd.it/bezueyk8b42c1.jpg?width=1500&format=pjpg&auto=webp&s=5826469e6b3580c4b2941f9cf412fa9628cbc10c