B767 flight crew was assigned an aircraft for a trans Atlantic flight that had a pack failure on the inbound flight. Maintenance sign off was 'reset pack;' problem reoccured enroute causing a diversion and aircraft swap.

Narrative

I was briefed before leaving the hotel by the inbound crew that the left pack had failed in flight and that maintenance was having parts flown in to fix the problem. Arriving at the airport we expected delays but were told that the left pack had been fixed. Sign off showed that they just reset the pack. In flight the aircraft started getting extremely hot verified by the flight attendants calling from the back. We tried turning the aircraft cooler at which time the left pack tripped. We followed the QRH procedure which includes turning the pack to standby; which did not help. Temperature in the back was indicating over 88 degrees. Also the ACARS failed which had also happened before to us on this aircraft two days prior. After discussion with the other pilots I decided it would be unsafe to continue our flight and called Dispatch. Dispatch agreed with our decision and said we would have to divert because we could not stay on the original flight plan. Dispatch said we would be under the 60 minute ETOPS rule. We agreed on the divert airport and agreed that I was an emergency aircraft due to overweight landing. He also said that he would start looking for a replacement aircraft. We made an uneventful landing with the fire trucks standing by. Once at the gate; Maintenance Control advised me that the left pack cooling door was completely loose. Also 30 minutes after landing; the #6 tire fuse blew. A new aircraft was assigned to our flight and we continued with no other problems.