Sign in with
Sign up | Sign in
Your question

Computer randomly shutting off

Last response: in Systems
Share
February 16, 2011 5:43:27 PM

My computer specs are to the left under my name.

It randomly just shuts off every now and again. Maybe once or twice a week. I don't remember this happening until I installed the second set of RAM (2x2GB Kingston) about a month or so ago. But my troubleshooting spidey sense tells me it's more of a power supply fault. The computer is positioned behind a bunch of junk. So it's kind of a pain in the neck to remove it, open it up, remove the new ram, and get it back together to test. Even then, the fault only occasionally shows face. So I thought I'd get some of you guys thoughts first.
a b ) Power supply
February 16, 2011 6:38:17 PM

You could run Memtest to make sure the mem sticks are OK, then take it from there.
m
0
l
a b B Homebuilt system
February 16, 2011 8:00:40 PM

Well, does it shut down and stay off, or shut down and restart? That by itself would go a long way toward figuring it out.

Also, if you suspect the memory, tell us the full specs of both sets. I see that they're different brands; if they're using different speeds, timings and especially voltages, that could be causing instability; the motherboard is likely picking the wrong one if you leave it on "auto." It could also be that you're having instability simply because all four slots are filled, in which case it can usually be fixed with a small voltage increase.

Personally, if you can get it to work with 4GB of RAM, I'd just leave it that way and forget about the other two sticks. Not worth it. You don't see much improvement in anything except video editing and serious multitasking by going from 4GB to 6GB.


Also, I assume your PC is around 3-4 years old based on the specs? At that age, it's entirely possible the power supply is going on the fritz, so that's the next thing I would check.
m
0
l
Related resources
February 16, 2011 8:54:54 PM

Just completely powers off and stays off. Typing along, then boom, nothing. I have to press the power button to turn it back on. Most of the time I can reach over right away and hit it. But a couple of times, I'd hit the power button and it would flash power on for a second then back off. I left it alone for 15 minutes and then I was able to boot it up. Really makes me think power supply.

Ok. Hour long full Memtest complete. It recognized all 4 sticks and I had no failures.

Some info on the RAM:
OCZ OCZ2N10662GK DDR2-1066 2.1V-2.3V 5-5-5-15
Kingston KHX8500D2T1K2/4G DDR2-1066 2.2V 5-5-5-15

According to memtest, here are the settings set in bios:
CPU FSB 277
RAM 346Mhz(DDR 693)
Cas 5-5-5-15

I know a little bit about these numbers, but I get a little confused on how the RAM speeds move in relevance to FSB setting... then you throw in dual channel settings and I'm lost. Does the DDR 693 mean my ram is severely underclocked? Or because it's in dual channel mode, it's actually double that and overclocked?

And most importantly, you think any of this is my problem?
m
0
l
February 16, 2011 9:27:22 PM

CPU-Z shows:







Is it just me? Or does it look like everything is underclocked?
m
0
l
a b ) Power supply
February 16, 2011 9:29:44 PM

I would check temps at this point. Make sure the heatsink did not get nudged while installing the RAM. Even so, I would re-do the thermal paste, just to be sure, if the system is old, likely the old application hardened up and cracked all over.
m
0
l
a b B Homebuilt system
a b ) Power supply
February 16, 2011 10:54:23 PM

Usually a memory problem results in a bluescreen and a reboot. A complete loss of power is usually due to 3 problems:

  • Bad power supply
  • A thermal sensor safeguard has been tripped
  • There is an electrical short

    Download and install HWMonitor and run it. Check your voltages. The +3.3V, +5V, and +12V rails should all be within ±5% of target. Therefore check:

    +3.3V: 3.14V to 3.47V
    +5V: 4.75V to 5.25V
    +12V: 11.4V to 12.6V

    Be sure to check at idle and when the system is being stressed under load. If any of the values are out of spec, get a new PSU.

    Also in HWMonitor, watch your CPU temps at idle and again under load. The CPU should be less than 70°C. Above that temperature in the 80's or higher and it may throttle or even shut down the PC. If temps are high, try new thermal compound and re-install the heatsink... maybe consider an aftermarket heatsink.

    If voltage and temps are good, you may want to explore the memory as a cause or check your installation for shorts. Check for motherboard standoffs that were missed during installation or maybe some obvious scorch marks on the PCB.
    m
    0
    l
    February 17, 2011 1:06:43 AM

    Thank you for the outstanding replies guys. Seriously.

    HWMonitor shows all three voltages stay within spec (unless it just spikes up or down and kills the PC instantly). The +12V rail is close at 12.54V.

    Some things I've changed. The Vcore voltage was abnormally high for some reason. CPU set stock and everything set to Auto in BIOS. And as you guys can see, the RAM was underclocked too. Again, everything on Auto in BIOS. The CPU temp was around 55 Celcius at idle. Pretty high I thought.

    So I switched Vcore voltage to manual and set it at 1.425V, bumped up the FSB a touch (2.65GHz now), set RAM voltage to manual, bumped them up a touch, switch the RAM frequency settings to manual and calculated an end frequency of ~1000MHz after the CPU overclock. Everything seems ok for now. Temps are significantly lower. But the puzzling thing is that all my monitoring software, including inside BIOS, is showing Vcore at 1.38V (instead of 1.425V) and DRAM at 2.00V (I set it at "+0.2V"). These stay the same regardless of load present. Why are my voltages showing lower? I've tried to ensure all built in "motherboard auto tweakers" are disabled. Shouldn't be an auto-adjusting going on.
    m
    0
    l
    a b B Homebuilt system
    February 17, 2011 1:59:50 AM

    firebirdude said:
    Just completely powers off and stays off. Typing along, then boom, nothing. I have to press the power button to turn it back on. Most of the time I can reach over right away and hit it. But a couple of times, I'd hit the power button and it would flash power on for a second then back off. I left it alone for 15 minutes and then I was able to boot it up. Really makes me think power supply.


    That sounds exactly like a heat problem.

    firebirdude said:
    The CPU temp was around 55 Celcius at idle. Pretty high I thought.


    Yup, definitely a heat problem. If it's much over 40 at idle, that's when you start to suspect something's not working right.

    As for your RAM voltage: The default for DDR2 is 1.8V, so "+0.2V" would bring you to 2 volts. So that explains that. The Vcore I can't say for sure from what you wrote - but I will say that having it turn out lower and cooler than expected is a lot better problem to have than having it turn out higher and hotter.
    m
    0
    l
    February 17, 2011 2:12:50 AM

    It seems as though I'm seeing what is called VDroop. That explains the voltage difference I'm seeing... but doesn't explain why the Auto setting was soooo high.

    And I wonder why my temps are so high... Maybe I'll pick up some compressed air, remove the heatsink and clean it, reapply fresh thermal paste and reseat the heatsink.
    m
    0
    l
    a b B Homebuilt system
    February 17, 2011 4:15:23 AM

    Not a bad idea on a machine that age. Besides the heatsink filling up with dust, the thermal paste often will bake into a brittle mess over time ... so if you're experiencing heat problems, it's always a good idea to check.
    m
    0
    l
    a c 122 B Homebuilt system
    a c 144 ) Power supply
    February 17, 2011 4:45:07 AM

    firebirdude said:
    It seems as though I'm seeing what is called VDroop. That explains the voltage difference I'm seeing... but doesn't explain why the Auto setting was soooo high.

    That is why we do not like Auto settings. 1.536 volts is way above Intel's max recommended voltage of 1.50 volts.

    Set the RAM voltage to 2.2 volts (+0.4 volts). Set your System Memory Multiplier to 2.0. These two steps should increase memory stability a little. Don't worry about seemingly low RAM frequencies. Core2 systems gain very little, if any, extra performance from overclocking RAM.

    Considering the age of the system, it certainly cannot hurt to reapply the thermal compound. And XClio PSU's are known to be not particularly good PSU's.

    If you are using the stock heatsink with a Q6600, you should be able to run at 3.0 GHz with little or no increase in the (stock) VID.
    m
    0
    l
    a b B Homebuilt system
    a b ) Power supply
    February 17, 2011 11:00:15 AM

    Yeah, 50°C idle is too high. Did you happen to see what the load temps were? The VID of Intel CPU's can vary from chip-to-chip. An easy way to find out the VID of your particular CPU is to run Core Temp. VID is the value you should manually set in the BIOS for stock speeds or even a mild overclock. Be sure to note the VID when speedstep is not in play.

    And definitely clean out your heatsink and re-apply some good thermal paste. You can pick up some Arctic Silver 5 at your local Radio Shack. Be sure to do it properly.

    m
    0
    l
    a b ) Power supply
    February 17, 2011 11:05:07 AM

    Yeah, see my above post.
    m
    0
    l
    February 17, 2011 11:47:00 AM

    Thanks for your help guys. I'll work on it this weekend, but still unsure if all this was the cause of my power loss. I kinda doubt it, but who knows...

    So far so good though. :-)
    m
    0
    l
    February 19, 2011 10:46:46 PM

    So just to update.

    I removed the heatsink. The thermal paste was a little crusty. I've seen worse, but it certainly wasn't like toothpaste anymore. After cleaning both the heatsink and the processor with isopropyl alcohol, I applied AS5 exactly how AS recommends. Blew the heatsink fins down to remove dust and reinstalled it.

    Be sitting at idle for about an hour with a temp of............................. 37 Celsius!

    Started this thread at about 55 Celsius, dropped to about 50 Celsius by switching off Auto Vcore voltage. And now I just lost a solid 12-13 degrees by renewing my thermal paste. Will this solve my random shut downs? So far so good, but time will tell. Rock on!
    m
    0
    l
    a b B Homebuilt system
    a b ) Power supply
    February 19, 2011 10:51:36 PM

    Excellent. Even if that was not the reason for you sudden shutdowns, it is always a good idea to have your CPU run cooler since it extends its life.

    Let us know if you do not experience any more shutdowns.
    m
    0
    l
    February 27, 2011 12:37:43 AM

    Been a week without turn offs. Good. But not out of the woods yet.
    m
    0
    l
    March 19, 2011 1:17:57 PM

    Update.

    I'm still having issues. Sometimes 60 seconds after I turn on the computer. Sometimes after it's been on hours and just sitting idle.

    Really sounds like power supply. I think I've done enough troubleshooting. Think I'm just gonna bite the bullet and order a new PSU and hope it solves my problems.
    m
    0
    l
    March 19, 2011 1:42:14 PM

    lol Just shut off two seconds after that was posted. Had to log back on to see if it even made it. Ironic.
    m
    0
    l
    April 19, 2011 3:33:51 AM

    Update.

    Instead of buying the PSU like I said I was going to in my last post, I removed one of the sets of RAM (the old, smaller capacity, set). So it's been from March 19th to April 18th without a single random turn off.

    I had no problems with that old ram previously, just wanted to add more. So it seems using two different brand rams was giving me the problem. Despite them both having the same rated speed/timing, both running on different channels, running on the same channel, running with it's like stick, running with the opposite. All didn't matter. As of now, just the new ram is installed and no problems for the past month. Sometimes I would go a few weeks without a hiccup, so we'll see. But I think this is a new up and running record.
    m
    0
    l
    !