Computer Overheating after Power Outage

[Epos7]

I posted this over in the ASRock X99 thread in the SFF forum, but I'll probably get more views here, and it may not be specific to the motherboard.

Last week, my power flickered. Not enough to reset any of my clocks, but enough that when I returned to my computer it was acting strangely with all fans spinning at 100%. A power cycle was all it took to get back to normal.

This morning while I was at work, the power flickered again. It must have been a split second outage again, because none of the clocks reset, but it was enough that my NAS was shut down. My computer on the other hand, had all fans spinning at 100% and was getting pretty warm to the touch. This time a power cycle didn't get things back up and running. The computer would power on, but I had no picture on the monitor. I shut it down and let it sit for 20 minutes, then was able to power it on successfully.

I think what happened is the graphics card overheated, and probably needed time to cool down. The problem is I'm not sure why. What could cause the computer to run at max load for an extended amount of time after a brief power outage?

System specs:

Windows 10
ASRock X99E-ITX/ac
Core i7 5820K
Noctua C14
Corsair LPX DDR4 8GB x 2
Silverstone SX500-LG PSU
ASUS GTX 960 Mini
Samsung 850 EVO

edit - system exhibits this behavior any time power is disconnected

 

[Seithennin]

You may have had your power supply,motherboard, or videocard damaged from the power surge. You might also want to check and see whether the surge caused any bios settings to reset.
If you have power surges often at your location, i really recommend you invest in a UPS/Power conditioner.

A 600 watt or higher power supply would be best for that build..

 

[Epos7]

I restarted the computer to have a look at the bios settings but they hadn't changed. Things got interesting after I exited the BIOS. Rather than restart the computer shut down. When I tried to power it back on I got the same result as before with the graphics card fan spinning up to 100% but no picture. Again the solution was to let the computer sit for a few minutes and then turn it on. I had reseated the graphics card, so I imagine that's what caused the same behavior.

It seems to function just fine once it's up and running. Not sure what to point my finger at here. I think the PSU is more than sufficient for this setup. 140 watt TDP on the CPU and 150 on the GPU leaves plenty of headroom. Could be that one of them was damaged by the power surge, but I'm not quite sure how to narrow it down.

The power is usually pretty stable here but has had a couple of issues in the last few weeks. Looking into a UPS or power conditioner is probably worthwhile to prevent future hiccups.

 

[Seithennin]

If you have another videocard you can use, try that for a while and see if the issue persists.
another thing that most people never check would be the cmos battery, which can cause odd things to happen when its almost dead or low in charge.
a power surge almost always does some sort of damage to the power supply.
By the issues you have mentioned, the first thing i would try would be changing the videocard.. then trying a different power supply.

 

[Epos7]

Unfortunately I have no spare graphics card or PSU to test, being my first ITX & 4K build, my old parts aren't compatible. If I could get my hands on some, how would I simulate a power surge? Just unplug the power cord and plug it back in?

As everything seems to run fine when there are no power disruptions, I may just look at getting a power conditioner and leaving everything as is. I almost wonder if it's a BIOS issue more than a damaged component. If a component were damaged, I'd expect to notice issues under full load, and there are none. There is a setting in the BIOS allowing you to tweak the system behavior when there is a power disruption. I have it set to turn the computer off, but it doesn't seem to work correctly.

 

[Millerboy3]

You sir may be the prime candidate for a UPS. It is highly recommended with higher tier hardware as it could be anything at this point. The bad part is you will literally have to get parts one at a time and test them in another scenario to figure out the problem. When in the bios if you look at the PSU readings do they seem a little off at all? 12v+ ? 5v+ ? 3v+ ? Anything out of the ordinary? Considering everything is going funny, its probably best to start with testing the mobo, considering everything you have there acts weird after you turn things on, thats probably the place to start.

 

[Epos7]

Thanks for those suggestions Millerboy. What would be the advantage of a UPS over a power conditioner? I don't mind if my computer turns off during a power surge, just don't want it to be damaged.

I'll take a look at the PSU voltages when I get home today. I think I should also test to see if the behavior repeats if I just unplug the computer from power, or if it's just power surgers/reseating the graphics card that does it.

 

[Epos7]

Those PSU voltages look pretty good to me. Maybe the 12V rail is a little high.

I've figured out the computer exhibits this behavior any time it is disconnected from power, or if the CMOS is reset. I still can't decide whether to focus on the PSU, video card, or motherboard. The only way I'll be able to test those components is likely going to be buying another, unfortunately.