Great that I've found this forum... A week and a half ago, my D54250WYB board shut itself down overnight. At the time it was idling, and in the BIOS was an event "Processor Thermal Trip". I'm running Windows 8.1 x64, with the latest BIOS and drivers.
I had a look in the Windows Event Logs for unusual events or errors, and there was nothing eye-catching around the time of the event. I also saved the System and Administrative logs in case (or so I could look at them again should they be overwritten, especially to see - if it happened again - how much commonality there was).
I've since left the NUC running pretty much 24/7, save a reboot or two for Windows Updates, and have installed CoreTemp with logging turned on. The temperatures seem to be around 40-43C consistently at idle, rising to the high 40s/ low 50s on average during moderate to low activity (movie streaming from Plex server, file copies/ downloads etc.), with the occasional short-lived rise to the mid to high 60s, though very infrequently. The ambient temperature is 23-24C, and I should add that I am using a fanless Tranquil PC H2 chassis. While this would be the immediate potential culprit, the operating temperatures seem fairly normal (especially at idle, perhaps a little high during activity?) - if the chassis were the issue, I'm surprised I've not seen something more alarming in the CoreTemp logs.
My concern is finding out why this happened, and although it hasn't happened again, I'm left wondering whether it will. I've asked the guys at Tranquil PC and they don't seem too concerned, basically saying that from the CoreTemp logs, the NUC appears to be operating just fine (which is true enough).
Any ideas on the root cause? Has anyone else reported this?
I'm attaching the Event Logs - the Thermal Trip event occurred around 5.45am on 02 March 2014.
My setup is as follows:
ABEL H2 Chassis
Core i5 D54250WYB (latest UEFI BIOS from Intel)
Crucial CT240M500SSD3 240GB MSATA SSD
Samsung Spinpoint ST2000LM003 2GB 2.5 SATA HDD
2 x Crucial 8GB DDR3 1600 MT/s CL11 SODIMM (1.35v)
APC Back-UPS CS 350
Windows 8.1 Professional x64 (latest drivers from Intel)