As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L PACK TEMP EICAS MESSAGE ON TAXI OUT. ACCOMPLISHED QRH PROCEDURE. AFTER 5 MINUTES IN STBY N PACK INOP LIGHT REMAINED ILLUMINATED. AIRCRAFT BACK TO BLOCK. AIRCRAFT GROUNDED BY MAINTENANCE. LEFT PACK DEFERRED. AIRCRAFT RELEASED FOR FLIGHT.