SG 300-28 switch bricked?

[JackD-c]

Greetings,

I have a CISCO SG 300-28 switch, and I was upgrading it's quite old firmware today, first using older major versions of firmwares and boot images and then stpe-by-step using newer major versions.

When I've reached the latest firmware version (1.4.11.02) and had a successful reboot, I've initiated a reboot with restore factory defaults option via the web interface.

Now it seems switch is bricked, system led is blinking, and I can't access switch on it's old or default ip-address (192.168.1.254).

Any ideas how to start recovering from here? Should I get a 9-ping serial cable to access CLI?

[balaji.bandi]

Do the factory reset, connect the console and see what process going on or stuck anywhere ( post the booting logs to understand what is wrong here )

http://www.thetechfactors.com/reset-cisco-sg300-switch-factory-default/

https://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/sf30x_sg30x/quick_start/78-19252-01.pdf

[JackD-c]

Thank you for your advice!

The hardest part was to find a proper serial (straightforward and not null-modem) cable, because this model has the older 9-pin serial port.

After successful serial connection I have not spent much time with diagnosing the issue, I just activated the previous boot image and rebooted the device. With the older image it started without issues.

Then I continued upgrading image files with smaller version steps and finally I could reach the latest version with this method.

Just for get the knowledge: how to see the booting logs via serial connection? When the device starts it sends only strange characters to serial console.