PC randomly shuts down doesn't come back on with power button. Randomly comes on too.

[boco77]

PC randomly shuts down doesn't come back on with power button. Sometimes will come back on by itself for 10 min then off again

Hi,

I've had this problem ocurring for the past two weeks on this barely one year old modern PC. Basically its been shutting off after 5-10 minutes all by itself and not coming back on if I press the power switch. However, It will sometimes randomly come back on again during the day after a hour or a few hours or sometimes not even come back on by itself without doing anything. When it does come back on it doesn't seem to stay on for more than 10 minutes. and the cycle keeps repeating etc. But no matter how many times I press the power switch it wont come on like this after its switched off by itself. It only seems to come back on when it feels like it lol.

So I've tried a few things. Firstly I sent it back to where it was built last week as its still under warranty. They found no issues with it whatsoever, it was running for 48 hours down there running intense stuff like 3d mark etc. Not once did it go off for them. This makes me completely perplexed as to why its only happening to me??!

I got the pc back from them today and sure enough it still went off by itself about 5-10 minutes after loading Windows 7 and connecting everything back in - shutting down completely and refusing to come back on.

Its not a temperature issue as it has so many fans inside and coretemp says about 30-40 degrees for cpu (i5 3750k) and about the same for single gpu (gtx 670). Its not over clocked etc. Just shuts down randomly when just using net or even if its completely idle. It has a more than adequate psu 750w corsair bronze.

So I really dont know what to do here. The place that built it didnt experience this problem. I've tried taking things out one by one to see if it would eventually come back on but it didn't. Tried taking out both hdd's and having one or the other in there and it wouldnt come on. Minimum connections at the back taking out usb leads etc and made no difference.

Any ideas? I still think its the power supply and maybe they just got lucky that it stayed on for them for two whole days? But this seems kinda doubtful as it doesnt stay on for me for more than 10 minutes when it does come back on (which in itself is rare if its going to come on or not).

 

[Eeqmcsq]

If it stayed on for them and not for you, perhaps the power from your wall socket is unstable? Have you tried taking your computer to a friend's house and running the same tests?

 

[boco77]

Well I've tried plugging it into another room of my house and that didn't work. I also used a different plug block but no difference.

 

[boco77]

Would a socket suddenly start going wrong too? Everything else woks fine on the same socket.

 

[Ketchup]

Do you run it on a surge protector or battery backup? Do you know if they did? What power supply is in the machine?

If you can, a list of hardware will be helpful here?

From the sound of your initial findings (before you took it in), it could be a bad power supply, bad power switch, or bad power coming from your wall.

The testing they did would seem to rule out the first two. Computers can draw a good bit of power, depending on what's in it, and are pretty dependent on a constant flow of power with no battery backup, so I wouldn't rule out power at the connection just yet.

 

[boco77]

I run it on a surge protected power strip. I've tried another power strip and its no different. It also doesn't seem to be a Windows issue either as I've just had it turn off within five seconds of it coming on itself. The worst thing it never comes back on manually so its hard to diagnose. It only comes on by itself and that is completely random too. Sometimes it's a hour sometimes its dozens of hours. But if it decides to come on it won't be for more than five minutes anyway before its switches off again.

 

[Ketchup]

I run it on a surge protected power strip. I've tried another power strip and its no different...

Ask the store if they used a surge protector or battery backup when testing. Also, what kind of system are you posting on now? And have you tested the new computer on the same outlet?

I am not going to be surprised if you tell us it's a laptop, as a laptop's power system has to be much more forgiving.

Also, what voltage is coming from the wall at your location?

 

[boco77]

I'm using my ipad to post this as well as a MacBook Air. There's lots of things that were connected to that same outlet as PC but they worked fine and never switch off themselves. Speakers, TV, 360, two external HDDs, router etc. I unplugged everything except the PC as I thought it might be overloading but it wouldn't come on this way either.

I will ask them about how they ran it. I'll also try the PC downstairs as that might be running on different wiring to all the outlets upstairs. I'm resending PC back tomorrow but I really don't think they'll find any issues again.

How do you find out wattage on the wall?
It's a fairly new house built about 25 years ago.

 

[westom]

How do you find out wattage on the wall?

Voltage and wattage are completely irrelevant. Many are grasping desperately for straws.

Normal for all computers is an AC voltage so low that incandescent bulbs dim to 50% intensity. Are your bulbs changing intensity? If not, then ignore voltage and protector fears. your voltages are not dropping that low and are not spiking to over 330 volts. Surge protectors do absolutely nothing until 120 volts exceeds 330 volts (a number even printed on each protector's box).

Provide numbers from six wires. If that tech knew electricity, then it is a first thing he did. Any layman or teenager can touch meter probes to those wires, report a three digit numbers, then have a complete answer without doubt. No more 'it could be' speculations. IOW a power system (which is more than a PSU) is either known good or intermittent - without the phrase 'it could be'.

Otherwise use another diagnostic technique. Just keep replacing good parts until something works. Without numbers from those six wires, then the better informed cannot post any recommendations. The tool (a meter) is so inexpensive as to even sell in some stores for less than $7. Otherwise just replace parts until something works.

Meter numbers will define a defect immediately. Or exonerate the entire power system so that we can move on to other suspects. Computer will run and numerous other suspect will act defective (intermittent) if the power subsystem is not stable.