Hi Stanley,
Does this article help:
How to console into Extreme and Enterasys switches
Do you have a serial port or a serial to USB adapter?
Depending on the version that shipped with the switch, it may have Zero-Touch Provisioning enabled, which will automatically assign an IP address from DHCP to the mgmt port or to one of the other front-panel ports. That IP address will be displayed, one number at a time, in the stacking LED window. If DHCP isn't available, it will display its link-local address.