PC abruptly switches off at random times

[PP Mguire]

Ok I should have posted before =/.

Anyways, HWMon will only show accurate readings of your PSU voltage IF the board has good sensors in the right places. 90% of the time this isn't the case. If your PSU is faulty then the problem will be non-CPU vdroop or a voltage drop under load. This can be random if something internally in the PSU is going bad so it could very well be load causing the shut down. As was said several times something of this nature can only be caused by a few things. The #1 thing is usually heat related, and that 80c load temp could do it. The next thing would be PSU sending some negative juju to the PC and a shortage protect is tripping.

The easiest way to see if your voltages are getting too low is to load both the CPU and GPU at the same time using Prime95 and MSI Kombustor respectively. Then measure your 12v. You can sometimes use HWMon for this because if it's real bad it'll be low. Doing the above puts a real load on your PSU to effectively see if voltages are dropping dangerously low which is a norm for CM PSUs.

 

[bevolasko]

Ok I should have posted before =/.

Anyways, HWMon will only show accurate readings of your PSU voltage IF the board has good sensors in the right places. 90% of the time this isn't the case. If your PSU is faulty then the problem will be non-CPU vdroop or a voltage drop under load. This can be random if something internally in the PSU is going bad so it could very well be load causing the shut down. As was said several times something of this nature can only be caused by a few things. The #1 thing is usually heat related, and that 80c load temp could do it. The next thing would be PSU sending some negative juju to the PC and a shortage protect is tripping.

The easiest way to see if your voltages are getting too low is to load both the CPU and GPU at the same time using Prime95 and MSI Kombustor respectively. Then measure your 12v. You can sometimes use HWMon for this because if it's real bad it'll be low. Doing the above puts a real load on your PSU to effectively see if voltages are dropping dangerously low which is a norm for CM PSUs.

Thank for replying!

The minimum voltage I got with CPU and GPU at 100% from the 12V rail was 11.821V. It was a 10 minute test, the temperatures were flaming hot but I don't think it would have made such a difference if I left it on for more.

Also, the air outlet was cool and this could indicate that the air inside isn't circulating and that it's avoiding the hot hardware.

This baby will never quit unless you wait until it turns off by itself. The shortage protection tripping sounds plausible but there is also something unusual about the shut down that I haven't mentioned. When the PC turns off, it then automatically turns on by itself. Usually during POST or after a few seconds of boot the PC turns off again and repeats the process. When this happens I pull the plug so it doesn't turn on again.

After 30 minutes without power the PC can be turned on and used normally again.

 

[NickS]

I would definitely try a PSU, however my computer at home has similar issues sometimes. The only times that I can see it randomly rebooting is when I try to plug in a usb to the front usb slots without first grounding myself on the case. I do not have proof positive that I am shorting anything with static but it is possible. Maybe you have a short somewhere? Try to check your grounding, perhaps open the psu (carefully, so you don't touch the capacitors) and check the ground wire on there?

Food for thought.

Nick

 

[PP Mguire]

What were the 3.3 and 5v at? All you need to do is just give it a quick load to see how low those voltages go. Also I need to ask how you were monitoring the voltages.

Air outlet where? If you mean on the PSU, that is more than likely only because you're not putting that much of a load on it even with everything full blast. If you mean on the back of the case, then for sure. It should be at least pretty warm to your hand. Definitely an issue with the stock cooling solution going on with your i7. Those particular chips run toasty.

As to the shut downs, I'm now looking at only two options. CPU heat/stability, or the fact that you're using 4 sticks and it's finally starting to become unstable.

 

[bevolasko]

What were the 3.3 and 5v at? All you need to do is just give it a quick load to see how low those voltages go. Also I need to ask how you were monitoring the voltages.

Air outlet where? If you mean on the PSU, that is more than likely only because you're not putting that much of a load on it even with everything full blast. If you mean on the back of the case, then for sure. It should be at least pretty warm to your hand. Definitely an issue with the stock cooling solution going on with your i7. Those particular chips run toasty.

As to the shut downs, I'm now looking at only two options. CPU heat/stability, or the fact that you're using 4 sticks and it's finally starting to become unstable.

Minimum 5.016 and 3.344V which are perfect.

It's the outlet above the CPU but it may be sucking the air instead and maybe that's why I can feel the cool air.

The PC wasn't made by me and it initially had 2 sticks installed. The PC is around 3 years old and I got the extra sticks early last year.

Edit: I monitored the voltages using HWMonitor

 

[PP Mguire]

Try taking the other 2 sticks out and running it a while like that to see if it makes a difference. If the IMC is unstable due to a 4 stick configuration then it wouldn't show up in a memory test because those test the sticks themselves.

 

[bevolasko]

Try taking the other 2 sticks out and running it a while like that to see if it makes a difference. If the IMC is unstable due to a 4 stick configuration then it wouldn't show up in a memory test because those test the sticks themselves.

I'll do that.

 

[PP Mguire]

What's the verdict?

 

[bevolasko]

What's the verdict?

Probably not the RAM controller. Yesterday I removed the two new sticks and just now the computer switched off again while I was playing Minecraft and it tends to do it more often with Minecraft. Now I can't use the computer because it turns off a few seconds after boot.

 

[PP Mguire]

Alright. When was the last time you put a fresh install of Windows on this thing?