3Com 3C17709 Getting Started Manual page 57

Solving Hardware Problems 57
4 Power cycle the unit. If a further thermal shutdown occurs, and all
environmental conditions are satisfactory, return the unit to 3Com.
Error message indicating that the GBIC transceiver is invalid
The Switch has identified that the GBIC does not meet the minimum
requirements for the Switch and has disabled the port. To correct this
problem, completely remove the GBIC and replace it with a 3Com
approved GBIC. See "Approved GBIC Transceivers"on page 28.
Error message indicating that the GBIC transceiver is faulty
To correct this problem, completely remove the GBIC and then reinsert it.
Alternatively, insert another identical GBIC. If the problem persists,
contact 3Com Technical Support.