Using the LPC1778, and have noticed on some of the boards the LPC1778 stops running when the ambient temperature gets around 60C, have even see one stop running at 55C. Have been able to reproduce failure on returned units by putting board inside chamber and running up to 60C. Failure does not occur on all boards. Some can run at 60C for more than 24 hours with no issue, others have even been run up to 70C and still no failure. The ones that do fail, can fail within 20-30 minutes of the chamber reaching 60C, others might run for a few hours at 60C before failure. They are able to start running again by applying a reset, but if they are still at the higher temp, they will just stop running again. Datasheet says operating temp is up to 85C so surprised that we are seeing this issues 25C below the max temp spec. We are running the core clock at 120MHz. We have a "heartbeat" LED connected to the LPC1778 that the LPC toggles on and off when it is running, when the LPC fails at higher temp the LED stops blinking, and is either stuck on or off. Also, ethernet communication cuts out, when failure occurs.