NUC Freezes, suspect overheating

[buckeyestargazer]

I have a NUC  NUC7i5DNK1E  that is experiencing random freezes/shutdowns.  I suspect there is a thermal issue but I'm not sure how to identify it.  What happens is the NUC will boot up properly, but after applying some kind of processing load it will just freeze, screen goes blank and the case is warm to the touch even with the fan working properly.  Often when I try to restart, the NUC will power on and the fan will have a burst of high rpm, the fan will turn off, then the light will turn from white to amber.  This then repeats without the NUC booting up.  A short time later I can boot up the NUC properly.  I have taken the case off and cleaned the air vents and there is no blockage of air movement.

Also, when stress testing with Prime95 the NUC will freeze after a minute or two.  

I've been using this NUC for about 2 years now without issues.

One question, if the CMOS internal battery is bad, could that cause anything like this?  

How can I identify which component might be causing the overheating or shutdowns?  Common sense would point to the processor somehow overheating but there's no obvious cause.

Thanks in advance.

[n_scott_pearson]

Run AIDA64, HWiNFO64 or some similar tool and use it to monitor the processor temperatures while running the stress test. If the problem is due to thermals, this will allow us to verify that this is the case.

AIDA64 is, BTW, an app that you need to pay for, but they allow a 30-day trial. I find it superior to any of the freeware tools for its compatibility with the NUC products. Just saying.

...S

[buckeyestargazer]

Thanks for the reply.  I actually did watch the temps with HWinfo64.  Both processor cores held steady at 80-81C.  The motherboard temp was around 50C.  According to HWiNFO there was still about 20C left before shutdown.

I am now stuck in a boot loop.  The intel logo comes up followed by "Starting automatic repair".  This just boots/loops continually.  I can still get into BIOS.

[n_scott_pearson]

So it doesn't sound like the issue with the processor. What about your SSD(s)? SSDs run hotter -- especially any M.2 NVMe/SATA SSDs -- and will either throttle performance or fail (including via lockup).

It sounds to me like this may be the case here. You may want to unplug the system and let it sit for a half hour or so to cool down completely. See then if you can boot up and get past the repair phase. If you can, you may want to save any important data on your system drive as it sounds like it is failing...

...S

[buckeyestargazer]

I was able to get the NUC restarted, but right away everything was "choppy".  Mouse movements would hang and the NUC froze after a short time.  Thankfully I had done a clone of the M.2 SSD a few days ago before it really started having issues.  

I have a new SSD on the way, so we'll see if that fixes the problem.  Thanks for your help.  

[buckeyestargazer]

It turns out the actual problem was a bad memory module (1 of 2 in the system).  Since replacing the module I've had no problems.