Pc Shutting Down Randomly

Hi guys,im new here but i really need help with a dilema.About 6 weeks ago i upgraded everything on my pc except for my power supply.I purchased
-Gigabyte GA-P55a-UD3 Mobo
-i5 760 Processor
-4GB Trident Ripjaw 2000 DDR3
-GTX 470
-Pheonix Pro 60GB SSD
-W7 64Bit
Now i play a lot of BC2 and it was in a game in the first week of this PC that i heard an almighty bang and had a smoke and light show in my bedroom which all came from the PSU.After rushing to the shop and grabbing a new Corsair HX850 the guy informed me that it would be unlikely my VGA or CPU would be damaged and if anything my MOBO would have been the first casualty of an exploding PSU.Anyhow, i got home and installed the new PSU and things seemed fine for a day or two and something strange started happening,i would be in mid game and my PC would just lose power,i mean just shut down,no warning or anything.So through the process of elimination i started pulling stuff out and re-installing,even clearing Cmos and nothing would turn the PC on until i removed the Processor and re-installed it.However.this was the first of many times my PC shut down and after 2-3 re-installations of the CPU this failed and instead it seemed like the PC would turn on when it felt like it,anything from 20mins to 4hrs,it was a hit and miss game.So i went out and bought another GA-p55a-ud3 and guess what,the same bloody thing.So then i went and bought new Ram,8GB Ripjaw 1600DDR3..same thing.Sometimes my PC would work for days and other times it just shuts down.I thought it might be the Ram after that so at a mates hous e while lanning it played up,so we tried his paired OCZ and it still wouldnt turn on,we rattled our brains all night.Thinking then it may be the case On/Off switch we disconnected all front panel connectors and tried to kickstart the power switch on the mobo with a screwdriver and still nothing.Drove home that night and set my PC up and it turned on after 4 goes.I know its not dust as everythings brand new,its not overheating as my CPU doesnt break 45deg O/C @ 3.8 and i also bought an Arctic Circle Accelero Xtreme Plus cooler for my VGA and now have it running stable at 1087mV/800MHz/1600MHz/1815MHz and passing 3Dmark11 and Kombuster.Before you say its because ive O/C'd everything this cant be possible as the PC was doing this before i tinkered with overclocking.Cant be the Mobo as im on the 2nd Mobo and its doing same thing,cant be the ram cause ive tried 3 different types that work in other systems and cant be the case or a shorting of the front panel cables cuase it does the same thing when i start it with a screwdriver.Im stuck :cry Im leaning towards a faulty PSU,hard to beleive as its brand new and a good name plus its silver series or have i damaged the CPU in the first PSU explosion and now it just shuts down cause its faulty? It seems so temperamental,i press the button and it wants to start but nothing.Even 3 times ive pressed the On button and the light comes on like it wants to start but it shuts down...then 5 secs later it comes on by itself!! <After this im leaning towards a faulty PSU but im just not sure.Next step is a new PSU or any other Mobo than a Gigabyte.Why does it come on only when it feels like it and why does it shut down for no obvious reason? :confused
Please Help
.

 

WOW!!!
My first thought is that there is a bad connection in the power supply circuitry somewhere - not necessarily in the PSU though. You have enough power coming through to light up the ON button, but not enough to get the thing going. Then the bad connection picks up and away it goes. Some time later, the bad connection drops out again, and the thing turns off. Does that theory fit with everything you have observed?

If so, check all your connections from the PSU. Also make sure the power cord (the one that goes to the wall plug) is good and working. Have you tried a different one?

Does the ON button stay lit while it's not booting, or does it go out and then later it comes on again and the computer boots?

 

Id like to add also that i have removed the battery for well over an hour on many occasions and also tried 4 different power cables,also different power points in many different rooms.Tried another video card and still wouldnt power up.The lights come on and then turn off straight away.When this baby is working its a complete rocketship and then it just falls from space with no warning.A few times it also stuck/froze on windows loading up screen and after hours of that we finally worked out it was the stupid USB3.0 ports,as soon as i took the mouse and keyboard out of those sockets and into normal 2.0 sockets it loaded up.Im telling you this as maybe its something to do with the Gigabyte Mobo,could it be the energy saving thing? :confused

 

The light doesnt stay on when booting cause it doesnt get to the booting stage,it just comes on for the moment i press the Power on button and then it dies.I have checked all connections from the PSU more times than i can remember,pulled them out,put them back in,pulled them out,put them back in..catch my drift lol.When it turns on it works fine but it just shuts down randomly.I wasnt even gonna post in any forums but i thought if someone else is having this problem and we find a solution than i can be of help.

 

Another funny thing is i was going out to buy a new CPU cause im at the end of my rope....and then it turned on and stayed on.I wouldve gone and wasted money on a new CPU when the old one works,you knowwhat i mean? What if i buy another PSU and still get the same problem lol. 2 X PC lol, but i only want the one.Im not happy with Gigabyte but yet after ive replaced just about everything else could it be the PSU? Do i need a 1000w, is the 850 not enough or is it faulty...grrrrr

 

Only at certain times.It does work,it has worked,ive stressed this thing like no tomorrow when its going

 

I suppose you could be short on power for that rig... not something I can advise on. I suppose you got advice from the shop when you bought the PSU. You would think they would know.
Have you tried a different mouse and keyboard (seems there might be some problem with them, from what you've said)? Maybe they got damaged in the explosion. You've replaced everything else, but you didn't mention those items.

 

Im on my 2nd G500 mouse and 2nd logitech keyboard.The old ones were fine lol and, well, i have new ones now.Ive tried starting without any peripherals plugged in at all and i get the same thing.Its definately a power problem,but why does it work and seem to have enough juice when its running for days and then other times it just turns off? Ive O/C everything hard and gone in gaming and its been great for days,running smooth and cold...and then BAM! It doesnt wanna play until its ready :major

 

Things replaced
Mouse
Keyboard
Mobo
Ram
PSU
Things not replaced
CPU
SSD
VGA
DVD rom

2 Main things would be the processor is yet to be eliminated and a possible faulty PSU.And throw crappy Gigabyte into the pot and it looks like slop.

 

It seems something is not letting the power stay on.Would a SSD do that? I wouldnt think so.Would a CPU do that? Im guessing yes eg. 'it gets hot it shuts down.'

 

I was thinking you could try booting without the CPU, but I have a suspicion you could only do that (to check the BIOS) on older PCs.
Any doubts about the SSD?
Can you take the PC back to the shop and ask them if it could be the PSU?
Gotta go.Happy New Year from East Coast Australia!!!:tas

 

Happy New Year to you to mate,im from east coast of oz too.No doubts about the ssd really.If a CPU is so intricate would a large vibration shut it down? Ive smashed the desk twice before during gaming with my fist and the PC shut down.I mean a couple of times while pulling things out and re-installing them its like ive moved something back into place and it works.Like my first post, i drove home and it worked.could the vibration from the car have resetelled something in the CPU.Id like to think its crappy gigabyte mobo or faulty CPU.I wouldnt like to think its the PSU as Corsair is an awesome brand and its straight out of the box.

 

Well, that was fun.:wave
I see we had crossing posts, as well.

It would seem fairly safe to assume that the problem that prevents booting is the same as the problem that is causing shutdown... but it may not be.
If not, you could have overheating (of SSD or CPU, I would think, although I don't know much about SSDs - anything can get hot though) causing shutdown - have you got any CPU/SSD temp monitor available? After it shuts down, does it reboot straight away, or after some time (when it's had time to cool down maybe, if you get my drift)?
This doesn't explain the booting problem though. I think a faulty CPU might cause that. You could always go and buy one - your second PC will need it.

 

Crossing posts again.
Well, as I suggested in my first post, it could be a faulty connection that is sometimes OK and sometimes not. Could be in the CPU, I guess. If you're brave enough, you could try booting, and poke around in the wiring at the same time, to see if jiggling any of the wiring makes a difference. Watch out for electric current though, and static (had to say that). Do the same while it's running, and see if anything stops it. If doing this fries you, I'm not here. You could try it with a non-conductive material, like your mum's fave spatula or something.

 

If you suspect the CPU, have you checked or reapplied new Thermal compound?
Not too much. Thats as bad as none at all.
Ensure that the heat sink is making good contact and is securely mounted.
Also may be something as simple as a defective power button switch. Have seen that before.

 

After it shuts down I try to start it straight away but nothing.I run a w7 gadget and CPU temp and it runs cold with the H70. It's not overheating from what I can see.I try and start it hours later when it's cold and it doesn't want to turn on still.To answer you hrlow2 I have remounted the CPU at least 20 times in it's short life so I'm confident of that, I am however curious about your comment on thermal paste. Yes I have re-applied paste and I'm guilty of laying it on thick, it's currently probably more than it should be so why and what does too much do?am I correct in saying it wouldn't dissipate heat efficiently if there is too much causing the CPU to overheat and shut down? I've tried to start it with a screwdriver and no panel connectors at all and same thing, light comes on like it's getting power and something stops it.Then why won't it start up again or only when it feels like it when it's cold?If you gurus can crack this I'll be amazed.

 

Isn't it past your bed time K2roo? I wonder what time it is in West Virginia.
If the thermal paste is applied too thickly, it won't conduct the heat properly to the heat sink (pretty much as you said). It's just supposed to make a good seal - take out any air gaps (air is a poor heat conductor).
You can rule out overheating though, according to what you've said. And if it was overheating, it should start again when it's cooled down. Still sounding like a poor connection somewhere - suspect solder joint, broken wire or connection... something like that.
I wonder if something could be shorting out on the case. What about loosening the screws on the MOBO, just in case it's touching somewhere (loosening the screws might allow the board to a bit more space behind)? Any chance one of the MOBO screws is touching a circuit, as another option?

 

Hi

It's VERY important when installing (or reinstalling) the CPU to completely clean the CPU and heatsink of the thermal paste that was on it, and apply new thermal paste. Clean both surfaces with rubbing alcohol and paper towels, and make sure they are dry before applying new paste. Use a good quality thermal paste (Arctic Silver 5 is good), and only apply an uncooked rice grain sized amount on the center of the processor. You definitely do NOT want to glob it on.

Also, your new Corsair HX850 is plenty of juice for your machine.

 

Ok i will remove CPU and clean and i will also check if any of the screws are shorting.Ill get back to this thread with an update.

 

Ok well GCW i pulled the guts out again and removed the Mobo to see if there was some sort of contact between the Mobo and the case mountings.Out of the 9 screw holes there was one in the middle of the board roughly where the VGA sits that you could visibly see where it has rubbed the enamel from the board and exposed 2 metal tracks.(I have a photo but cant find my iphone cable to uplaod it but will do when i find it).So i cleaned the holes and mounting points with acetone and cotton buds(Qtips) and re-installed the Mobo.I turned the power on and it died again.Scratching my head and sighing i knew that this 'exposation' has something to do with the situation,so i grabbed the VGA and physically pulled it,thus moving/dis-lodging the mobo from the case hoping that it would create some gap between the freshly cleaned Mobo and case mountings.I pressed the power button once more and 'HEY PRESTO'. Houston we are clear for lift off.Im almost certain that this is the problem,im no PC expert and only know how to put them together so through the process of elimination and replacing many bits i beleive that there is a shorting here.Now im not getting ahead of myself,i anticipate this will happen again but next time i will put one of those gasket washer thingies in that particular mounting to break the short.Thanks for your suggestion GCW
"I wonder if something could be shorting out on the case. What about loosening the screws on the MOBO, just in case it's touching somewhere (loosening the screws might allow the board to a bit more space behind)? Any chance one of the MOBO screws is touching a circuit, as another option?"

 

Keeping fingers crossed.

 

heres the culprit :cry

 

Nice.
Looks like that would be the culprit, all right. Uncrossing some of my fingers now.
And congratulations on finding your iPhone cable, too. Must have been difficult with all those other computer bits you now have! :-D

 

That wasnt the problem,it just shut down again today and im not happy.I tried another case today,cleaned the processer and used minimal thermal paste.I just dont know.Somethings faulty and everything is new except the cpu.I was gaming all day yesterday and this morning but then it just shut down. i give up.

 

Zut alors!!!
Was it hard to get it to reboot again? Or same as usual?
Can you borrow a different CPU to try?
Have you checked the W7 error logs, to see if it's telling you anything.
Any setting in the BIOS that might be causing it?
I'm assuming (hoping) you haven't really given up.

 

Borrow a different CPU i cannot. I did mange to get into W7 repair diagnostic and all times said nothing was found,did the memory test and nothing was found also.Not sure about a Bios setting.When and if i get in again i will check theres no auto shut off enabled.It starts,works,shuts down.My guts are telling me gigabyte mobo's unreliable.Hopefully i can go out and buy an msi mobo this week. ive had enough.

 

I feel your pain.
Try loosening all the screws on the MOBO, just in case there's a poor connection caused by some distortion of the board... if you can be bothered.

 

I put electrical tape on all case mounting points and underneath the mobo on the mounting holes and got nothing. Then i pulled everything out of the pc and set it up on static bags on a wooden desktop and still got nothing. Thats when i tried a different case and still got nothing.I dont beleive its the case or a shorting out on the case.
1.Either the CPU was damaged in the initial voltage spike from exploding PSU and its shutting down randomly cause its stuffed
2.Very unlucky but have i received 2 faulty Gigabyte Mobo's in a row or
3.Is the brand new Corsair HX850 faulty
By the way GCW if it wasnt for you,hrlow and mcsmc in here i wouldnt have any help. Thanks for helping.

 

Happy to help. Not the right help, unfortunately.
I hear what you're saying about those options, but things like the PC starting when you pulled on the video card still make me think there's something electrical going on. That could still be related to the CPU etc, as there could be wiring problem with one of them, and pulling on the card could have restored the connection. A broken wire, for example, would be difficult to detect.

 

Yes but a broken wire where? In the PSU? There are no wires in the mobo and since the last shifting of the VGA I've moved everything again and nothing. I just ordered a MSI p55-gd65 so after I pit that in if it keeps doing it then I'll go another CPU.

 

May not be any wires on the board, but those very fine circuits are able to get scratched and broken.
Would be very hard to see.