Why does my PC turn off?

This may be a hardware problem, who knows? I am truely, totally baffled, and on the point of starting to be ready to commit physical violence.

Second hand PC, but fairly powerful hardware.

The weird thing is it just turns itself off. One moment you are doing whatever, and the next it shuts down. It does not do a shutting down process, but simply turns off. I have adjuested all the power saver settings so they do not apply, and this has made no difference. The CD/DVD is defective, so I am using an external one if this makes any difference. Some one please help before I jump off a cliff! There is no set time, but usually around 15 minutes.

 

Heat.

The symptoms you describe point to above - your CPU is getting heated & shutting down. Open the case & clean inside with compressed air - your CPU heat sink would require special treatment.

While the case is still open, switch on the computer & note if the CPU fan is working properly or not. If it seems to be running slowly, you may have to replace it.

Get into BIOS/CMOS setup. There would be some page which would display CPU voltage, temperature etc. Find it & let it run for a couple of hours on this page only - note down the starting temperature. If it reboots/shuts down or the temperature climbs up by more than 6-7 degrees, you have a heat problem.

 

Hi, Kiwi. Welcome to Windows BBS!

The two times I had problems with my computer abruptly shutting down (powering off with no "Blue Screen of Death" a.k.a. "BSOD "), the culprit turned out to be a flaky power supply unit (PSU). I have a friend who also solved his problem with abrupt shutdowns a year or so ago by replacing the PSU.

If you have a spare PSU handy that has enough power (watts) to handle your system's hardware, try swapping your PSU. A PSU can probably be purchased locally (i.e., at Best Buy) for $30-$50.

Alternatively, you can purchase a PSU via an online retailer such as Newegg. Newegg has an excellent reputation for their prompt shipment. I also have always had prompt shipments from Newegg when I ordered items from them.

Even if the PSU is not the culprit, you'll have one handy the next time you experience a similar problem.

Please post a follow-up to let us know if rsinfo's suggestion or my suggestion solves your issue or not.

 

To help with rsinfo's suggestion, you may want to try using a system information utility such as EVEREST or Aida32 if you don't want to mess with going into your computer's BIOS setup utility. They may be downloaded via this Major Geeks link. I use EVEREST Home (Free) Edition version 2.20.405 to display the CPU temperature, fan speed, etc. information that rsinfo mentioned above.

When you use compressed air to clean your fans and CPU heatsink (with the computer's power OFF), be sure the compressed air does not cause the fans to rotate. Gently hold the fan blades with your finger to prevent fan rotation because the fan rotation creates electrical current that may damage your system.

Compressed air is probably available in cans at your local computer supply retailers.

If you separate the CPU fan from the heat sink to better access the heat sink for cleaning, do not separate the heat sink from the CPU. The heat sink must remain well-fitted to your CPU. Otherwise, you'll have to mess with reseating the heatsink to the CPU which will probably be tedious and potentially dangerous to your computer's operation (involving cleaning off the bonding material and carefully applying fresh thermal paste/grease).

To help compare your system's information to mine, here is my information as reported by EVEREST in the Computer > Sensor section:

Code:

[B]Temperatures:[/B]
      Motherboard       31 °C  (88 °F)
      CPU               43 °C  (109 °F)
      GPU               61 °C  (142 °F)
      GPU Ambient       42 °C  (108 °F)
      (My Hard Drive)   31 °C  (88 °F)

[B]Cooling Fans:[/B]
      CPU             3857 RPM

[B]Voltage Values:[/B]
      CPU Core          1.74 V
      +3.3 V            3.26 V
      +5 V              4.87 V
      +12 V            11.97 V
      +5 V Standby      5.03 V

 

Well, mailman, I have never thought of that before but never had any problem either. Thereotically it can happen, but to get abnormal voltages (above .5-.7 V) you would have to rotate the fan at very high speed. But better to take precautions - would keep that in mind in future. Thanks a lot.

 

Well, I think you guys have picked it. Thinking about it, it was rather obvious.

I used the excellent PC Wizard to keep tabs on the PC. After about 5 minutes running ( the time it took to install the utility), I checked the stats every minute..

Processor: (degrees C)- 50, 51.5, 53, 51.5, 55, 55.5, 56.5
Mother Board: ( degrees C)- 24, 25, 26, 26, 27, 27, 28
Hard Disc: (degrees C) - 21, 21, 22, 22, 23, 23, 24
Fan Speed: 2743, 2743, 2743, 26743, 2743, 2743.

Undoubtably a heat problem. So, I will get it fixed. I get the feeling the fan may wel be running far too slowly, and I suspect it was damaged when we shifted house recently.

MY next question is this: Have I done any damage do you think?

 

You've gotten some very good advice re: temperatures, heatsink cleaning, Power Supply and fan bearings and, you've been given a couple of excellent references to check out your actual temperatures. The comment about heading into your BIOS and checling temps from there is going to be considerably more accurate and meaningful and the reference point disparity (rise in temps) information you were given can be a good problem indicator. You want to test while in the BIOS because it puts a minimal load on your system hardware.

From what you have posted, I would say, "No Great Shakes - Keep Looking ". From a cold start, your machine's temperature readings are quite normal. You would be well advised to follow rsinfo's suggestion to let it run for a couple of hours while in the BIOS or alternatively, use Everest or it's predecessor and open that sensor page then open a bunch of other stuff up and tax your machine for a while - push it with some intense activity and keep your eye on that sensor page or refresh it if in a more recent version. Gauge your temperature swings in this environment and use something more like a 10° C CPU variance to determine if you have a heat related problem. (That cool little 43° number mailman has next to his 3200+ will take quite a ride when he gets into heavier activity - I'll let him give you his specifics)

Personally, I hope a good cleaning works for you but don't get discouraged if you find out you really do need a new PSU or that your graphics card cooling is the real issue - sometimes these things can be elusive and there are several potential causes. Finding the "cure" often requires a systematic elimination of what it isn't before one can settle on just exactly what it is.

Again, I hope you found your answer but keep us posted in the event there might be a little more to it. Good Luck.

 

Thanks ever so much for your help guys, I wish I could repay the favour. If you ever want any advice on what firearm to buy, let me know!

I am beginning to suspect the graphics card. It seems to run OK on normal apps, but when you start gaming is when things go wrong. FOr example, I cannot load Warcraft- it gets to disc two and dies. If I load a PC game, you get about ten minutes of fun, then bammo, down it goes. I will give it a clean and see. Thanks again.