3Com SuperStack - Recent Questions, Troubleshooting & Support

Well I think the port is bad, I had one that did something similar to your problem. I got on the 3Com website and submitted and RMA request and they upgraded my with the newest model. But if yours is still in stock they will replace with the same type. That is what I would do. Hope this helps ya.

sound like its fails the post.manual says should yellow if it fails, green if it passes. maybe hard reset unplug it from power wait a couple minutes plug back in.

Connect some text-based terminal emulator such as Hyperterm, telnet,VT100, etc to the serial port. Configure the emilator to19200 Baud 8 plus none. Switch the 4924 on and login using the user "recover" (without quotes) and password "recover" (also without quotes. The switch will go into recovery mode. It will display a count-down starting at 30 seconds. If you power thye switch off before the count is up, the default password for the main administration account "admin" will be cleared. After a few seconds, power the switch on and set a new admin password. After loigging in again, take the option "GettingStarted". Configure the ip settings (best to use a static address) and eventually you will get to the "Initialize" option. Enter yes, and after reboot it will be at factory except for its ip address.

1. Faulty power supply
2. Heat issue

See if there are any logs on the switch that you can check for errors. If you can't I suggest you call 3Com for troubleshooting.