PC doesn't come on - sometimes randomly will briefly but goes off again by itself.

[boco77]

I've had this problem ocurring now for the past two weeks on this barely one year old PC that I bought from PC Specialist.

Basically its been shutting off after 5-10 minutes by itself and not coming back on even if I manually press the power button on the case. However, It will sometimes randomly come back on again by itself without pressing anything during the day. This happens usually after a few hours but even this is pretty random and may only happen once or twice in the day or not at all.

If it does come back on it doesn't seem to stay on for more than 5-10 minutes. This cycle just keeps repeating. No matter how many times I press the power button on the case, it never comes on like this after it has switched off by itself. It only seems to come back on when it feels like it lol. I can see the motherboard light is always on through the case. But the machine itself won't switch on.

So I've tried a few things. Firstly I sent it back to you guys 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'm disappointed that you guys couldn't at least change the power supply rather than just sending it back as it came as honestly this is most likely the cause. I have no idea why it stayed on all the time for you but when I got it back yesterday it went off again after 5 minutes of switching it on. Wouldn't come back on after that. Randomly came on twice during the evening for like 5 minutes each time. Basically the same exact problem prior to sending it.

Its not a temperature issue as it has so many fans inside and coretemp says about 30-40 degrees for cpu (i7 3770k) and about the same for single gpu (gtx 670). Its not over clocked etc. Just shuts down randomly when using net or on desktop etc completely idle. It has even happened while its booting up (basically within 10 seconds of it coming on) so its not a software issue. It has a more than adequate psu 750w corsair bronze.

I've tried taking things out of the computer one by one to see if it would eventually come back on but it hasn'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 with just the kettle plug from psu going to wall outlet and it made no difference. Even tried a different kettle plug lead too.

I tried it in different wall outlets upstairs and downstairs. Tried different surge protected plug blocks, tried it with nothing else plugged into the wall sockets but it made no difference. I've had absolutely no other issues with any of my other devices in the house whether its consoles, kettle, TV, lamps etc nothing else has ever gone off by itself like this.

I still think its probably the power supply as I've had this kind of thing happen before to past PC's and sure enough when I replaced the power supply it would start working but I don't really want to mess with the psu myself that's why I sent it to you. It's been rma'ed again and someone will be picking it up tomorrow. But honestly I don't have much faith now after it was just sent back without any changes with the same issue existing.

EDIT: I've attached a video

View My Video

My specs:

Case InWIN WHITE DRAGON RIDER GAMING CASE
Processor (CPU) Intel® Core™i7 Quad Core Processor i7-3770K (3.5GHz) 8MB Cache
Motherboard ASUS® SABERTOOTH Z77: USB 3.0, SATA 6.0GB/s, THERMAL ARMOR
Memory (RAM) 16GB SAMSUNG DUAL-DDR3 1600MHz (2 X 8GB)
Graphics Card2GB NVIDIA GEFORCE GTX 670 - 2 DVI, HDMI, DP - 3D Vision Ready
Memory - 1st Hard Disk 120GB INTEL® 520 SERIES SSD, SATA 6 Gb/s (upto 550MB/sR | 520MB/sW)
2nd Hard Disk 2TB WD CAVIAR BLACK WD2002FAEX, SATA 6 Gb/s, 64MB CACHE (7200rpm)
1st DVD/BLU-RAY Drive 24x DUAL LAYER DVD WRITER ±R/±RW/RAM
Power Supply CORSAIR 750W ENTHUSIAST SERIES™ TX750 V2-80 PLUS® BRONZE
Processor Cooling SUPER QUIET 22dBA TRIPLE COPPER HEATPIPE INTEL CPU COOLER

 

[keynes]

I'm disappointed that you guys couldn't at least change the power supply rather than just sending it back as it came as honestly this is most likely the cause. I have no idea why it stayed on all the time for you but when I got it back yesterday it went off again after 5 minutes of switching it on. Wouldn't come back on after that. Randomly came on twice during the evening for like 5 minutes each time. Basically the same exact problem prior to sending it.

If they didn't find any problems then I understand why they wouldn't replace the psu. Now going for a 2nd RMA I would indicate your concerns and request testing the psu for possible faults.

 

[nathanjrb]

Take a film of it next time too, I know you've explained it pretty well, but when I had a problem with my PC I just filmed what was happening and linked them to it on YouTube so they could see for themselves. As Keynes said - they won't replace anything if they can't find anything wrong with it but I would request some further tests on the PSU.

 

[boco77]

Take a film of it next time too, I know you've explained it pretty well, but when I had a problem with my PC I just filmed what was happening and linked them to it on YouTube so they could see for themselves. As Keynes said - they won't replace anything if they can't find anything wrong with it but I would request some further tests on the PSU.

Ok I've uploaded a video in the original post using this ipad somehow lol. Don't know if that will help but that's the problem.
Video should play but I can't see it on my ipad as it doesn't support flash obviously.

 

[nathanjrb]

Gotcha.

I would suggest checking the RAM. Remove them both and try them one at a time.

 

[nathanjrb]

Actually dodgy RAM wouldn't stop it from turning on, just from booting up I think. But the light on the MOBO suggests that power is reaching it and that the problem could lie with the connection between the MOBO and the on switch, or it could be a dodgy motherboard.

 

[steaky360]

It could be a dodgy power button. I don't know what jumpers you need to connect to 'jump start' the motherboard without pressing the power button (ie starting it without a case basically). Although if you're savvy you could give it a shot, trace the wire from the power button to the motherboard, it should be connected to a jumper, if you make that connection with (for example) your finger (NOTE: ensure you are sufficiently earthed for the sake of your components etc.), the board should start up straight away. If it doesn't, there is a chance its the motherboard thats faulty, although PCS must have got it to start when they received it.

When you call them discuss this with them potentially prior to arranging another RMA, might be worthwhile?

 

[boco77]

Yeah I'd have thought as long as motherboard is getting power it would come on. It's likely a bad mobo, bad psu or bad connection to the power button or even a combination of those things perhaps.

I'd understand if it was shutting off playing intense games but it happens so randomly and comes on randomly too. There's no cool down periods. I been mostly at home today and its come on twice while its been connected to the mains. Once for about 2 minutes. It barely loaded up Windows 7 before shutting off by itself (no warnings, its like someone pulls the plug). Then it came back on about a hour later (it always beeps once when it comes in so i heard it from downstairs) but by the time I got to it about 10 seconds later, it had shut off again. I'm presuming it was still on windows loading screen so it looks like a power issue not software related. The mobo light is always on even when it switches off by itself.

As of now I've moved the PC to downstairs readying it to package to be sent off again. Connected to another outlet downstairs just to make sure but doesn't come on here either. Mobo light inside remains on as always. It's the weirdest problem I've ever come across for a PC and I've been using them since mid 90s. Why it doesn't work for me and it worked fine for the tech guys at PCS makes no sense.

 

[nathanjrb]

Why it doesn't work for me and it worked fine for the tech guys at PCS makes no sense.

It's called sods law mate

 

[moosEh]

We will hopefully find the issue with the system on its second rma.As its being sent in with the SSD

 

[boco77]

Ok thanks. Hopefully it should get sorted this time.

By the way I forgot to say I tried the PC at a friends house just to rule out the possibility it might be something to do with the electricity in my house but it didn't work at their place either.

 

[Androcles]

Get them to take a close look at the current on the 3v/5v rail, i had and issue a couple of years ago with a machine that sounds similar, it turned out to be a crack in the wire for the 3v/5v rail not letting enough juice through.

 

[boco77]

Ok just had a update after calling PCS. The PC has been with PCS for a few days now and so far they've had no issues with it switching off by itself or not coming on. This is not a good sign. I'm a bit worried now as I really dont want the PC back in the same state as the previous return. It's basically a massive £1500 brick that I only got last September.

For me the problem started happening a few weeks ago where it would ocassionally come on for about ten minutes (if it come on at all) and then switch off by itself after that.

Are you guys running it through a UPS or something like that as that could potentially be the reason enough power is going through to it to stop it from switching off perhaps?

 

[keynes]

Are you guys running it through a UPS or something like that as that could potentially be the reason enough power is going through to it to stop it from switching off perhaps?

You need to contact PCS directly over the phone or send them an email.

 

[boco77]

Hi,

Just to let everyone know the PC has been working fine since I got it back last Friday and have had no issues since. The power supply was replaced with a brand new one (same make/model) so it looks like this was the cause of the problem.

Even though this doesn’t really explain when I sent it back both times why it was working absolutely fine and never switched off whatsoever at PCS during testing with the previous power supply.

Although its working now, I’m a little concerned that this could happen again some months down the line from now. The fault report said there have been known issues in the past with this particular make/model of power supply where it intermittently can shut off (CORSAIR 750W TX750 V2-80). I would have preferred if the PSU was replaced with a different brand/model altogether but of similar spec.

Anyway at least it is working now. Thank you.

 

[nathanjrb]

Very pleased to hear it's all working.

I know what you mean about worrying further down the line. I had a few issues with my computer and ever since I've been constantly worrying - even though it's been perfectly fine. I'm in the middle of my dissertation so if it is going to break it would be great if it could wait until after friday

 

[Androcles]

Glad it got sorted for you. If it fixed itself by having a new PSU then it's very like a PSU issue, maybe something like what i mentioned earlier, if you're on the edge of your local power grid you could get drops in power which are usually with in tolerance levels and won't effect most things and if your PSU has week cabling or issues like cracks in the wires etc it could be enough to drop the power below the motherboards requirements, hence why you experience it and they don't, that's basically what my issue was which was exhibiting the same symptoms you had.

 

[boco77]

@Androcles: yeah it seems like this could definitely have been the issue after all. It's the only one that makes sense.

Anyway No problems after 4 weeks of use now. Thanks a lot for the input on here guys.