As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
During Climbout on Flight #3589, #4 Engine would not produce max cond. on departure without Over Temp.(Temp 648 for 19 Sec) Air return to MSP. Maintenance replaced broken Bleed Band and completed Borescope Inspection of Combustor and 1st Turbine nozzle due to Overtemp. Found to be serviceable.