Pc Random Shutdowns

OK so I built my current pc years ago and its been running fine (ish), ACPI x64, 2.4ghz quad core, 4 gb ram (2 x 2gb), GTS 250 gpu,

But this morning when I switched it on it has begun shutting down wheneer I try to run any programs, games or even go on the internet.

I have opened up tower and cleaned it out thinking it might be cloged with dirt, checked all fans are running and that nothing is overheating,

De-fraged, cleaned system files and run virus and malware scans, NOTHING.

Please help, was thinking it might be PSU but dont know how to test it, and I don't have a spare to swap it out with.

Yes I am building a whole new system AMD, but that is going to take some time and this system will be given to my young daughter to get her started, so I need to get it fixed.

Error logs attached

 

Neither of the attached reports appear to be related to the crash cause(s).

PSU or possibly the GPU would be my best guesses too, PSU testing requires specialist tools and loads, basic PSU 'testers' are close to useless, they can only test the PSU without realistic loads applied. To test the GPU, find a friend/colleague with a recent PC and good quality 450W+ PSU to test it for you.

Check also for bad caps: http://www.badcaps.net/index.php?pageid=identity

 

checked motherboard for bad capacitors, warping or loose connections / solders and cant see anything, also ran memory diagnostic and found nothing. Unfortunately just moved to new area so Dont know anyone yet.

 

Let's see if Digerati picks up this topic next time he logs in, he can describe what's needed for PSU testing.

 

Thanks for your words and thaughts, will keep trying things and hoping for ideas (maybee).

 

If you are able to get into safe mode.

Make sure you run command prompt as administrator be for doing these steps.

First try to run check disk for errors.

When in CMD Type as follow Chkdsk /F

It will most likely ask you to reboot system.Type Y for yes if the prompt comes up.

This part might take you a while.Depends on how big your HDD is.Same below.

Than

Try to Run the System File Checker

In command prompt Type SFC/Scannow This will run a file checker to see if your OS is corrupt or not.

 

Ran both these checks but no bad sectors or bad memory

 

Is there any type of heat issues.GPU or PSU things getting to hot.Have you cleaned out the dust lately.

 

There all so could be a computer virus or malware on that system.

I would run a full scans in safe mode.
Click this link.
READ & RUN ME FIRST Malware Removal Guide (incl. spyware, virus, trojan, hijacker)

Oh and another question when you where in safe mode did it shut down at all.There could be a program,Script,Macro on that system that could be causing this type of issue.

When count how long it takes to shut down or use a stop watch.

There have been lot's of reports of a virus that auto shuts down a computer.

 

Now I see why my ears were burning!

Sadly, there is no way for "normal" users to conclusively test a power supply other than to swap in a known good supply.

To properly and conclusively test a power supply unit (PSU), it must be tested under various realistic "loads" then analyzed for excessive ripple and other anomalies that affect computer stability. This is done by a qualified technician using an oscilloscope or power supply analyzer - sophisticated (and expensive) electronic test equipment requiring special training to operate, and a basic knowledge of electronics theory to understand the results. Therefore, conclusively testing a power supply is done in properly equipped electronics repair facilities.

Fortunately, there are other options that are almost as good. I keep a PSU Tester in my tool bag in my truck for house calls. The advantage of this model is that it has a LCD readout of the voltages. With an actual voltage readout, you have a better chance of detecting a "failing" PSU, or one barely within the required ±5% tolerances as specified in the ATX Form Factor PSU Design Guide (see “Table 2. DC Output Voltage Regulation” on Page 13). Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed". However, none of these testers test for ripple and they only provide a little "dummy load", not a variety of "realistic" loads. So while better than nothing, using one of these testers is not a certain test.

I am not a fan of using a multimeter to test power supplies unless you are an experienced technician. To do it properly, that is, under realistic loads, the voltages must be measured while the PSU is attached to the motherboard and the computer powered on. Testing at the main power connector requires poking (with some considerable force) two hard and sharp, highly conductive meter probes into the main power connector, deep in the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it. It is not worth the risk considering most multimeters, like plug-in testers, do not measure or reveal any unwanted and potentially disruptive AC components (like ripple) to the DC voltages.

The voltages can be checked in the BIOS Setup Menus of most motherboards but they do not reveal ripple or other anomalies either. And of course, booting into the BIOS Setup Menu requires a working PSU.

So my advice is to either buy another PSU or see if you can borrow one from another computer - perhaps from a friend. BTW, right now, Newegg has a really great deal on this top quality EVGA Gold 550W PSU.

 

Sorry for the delay in answering, have been out all day, Wile e coyote I ran all these tests at stupid hours last night as I said in my first post, but thank you for the suggestions. I have only just moved to the area so borrowing a power supply is not on the cards and I live in the middle of scotland and apparently newegg dont deliver here at reasonable delivery charges, (almost as much for delivery as it is for the power supply), however I'm thinking that maybee the best option is to buy the power suppy for the computer im building first, test it in this machine and if it solves the problem then buy a second PSU for this machine.

 

http://skinflint.co.uk/xfx-xt500-500w-atx-2-31-p1-500b-xtfr-a1408695.html?hloc=uk would run just about any non-overclocked PC with a GTX 250, or a recent GTX 970.

http://skinflint.co.uk/xfx-xt600-600w-atx-2-31-p1-600b-xtfr-a1408715.html?hloc=uk would run a GTX 980Ti (£500+ card).

 

Like the xt 600, think I might give that a run for its money, thanks for the sugestion and all the help. Think I can call this one a win even if I can't fix the PSU.