# Random PC Shutdown (no reboot)



## GroverXpup (Dec 4, 2007)

Ok here’s the problem and as much info as I can give in the hopes of figuring this out! I feel my PSU is the problem, but please tell me what you guys think!

The Problem: My computer will randomly shut down- DEAD (like you pulled the plug). The green light on the back is NOT ON when it does this. It’s usually on when my computer is on or off, but when this happens, it’s OFF (I have PC plugged into a UPS). The front power button blinks green and I have to press and hold for it to go off so that I can press the button again to power up. When I power up, it starts up completely normally (no errors, warnings, logs, etc.), as if it never happened. 

When it happens: Completely RAMDOMLY. It has nothing to do with what I’m doing (i.e. a certain application) at the time. I can be on for 7 hours and use my common apps (I don’t really have any real RAM intensive apps, I’m not a gamer) and I’m fine. Then next time I’m on for twenty minutes and it happens. Again, NO particular apps, sometimes I’m just on my desktop contemplating what to work on. Then, after it goes “dead,” I power back up and use it for the next 5 hours and it’s fine.

What I’ve tried: OK. I’ve tried MB Monitor and everything seems fine. I’ve run Memtest and it was fine for the two hours it ran, but then I had a dreaded “shut down.” Hard disk is OK according to tests I’ve run with my Seagate app. I’ve cleaned up my compy and defragged. Start up apps are only the necessary ones. All apps and drivers are up to date (as far as I can tell). I’ve vacuumed out the case and cleaned components, secured connections and physically inspected Mobo. I’ve run the diagnostics that came with my HP Pavilion and everything passes (RAM, Graphics, Hard drive, etc.).  I unplugged all unnecessary hardware, like my external hard drive. I’ve reset the BIOS to default. 

I’ve tested the PSU with a PSU tester (everything was fine which is no surprise because when it’s on it works perfectly until it DOESN’T), but I have not tried a multimeter. I have a small PSU (200 watts), but it’s always worked fine and I haven’t upgraded any components in the last couple months (this has been going on a couple of months).

My gut feeling is that this is the PSU, but I’d like some feedback! I don’t want to mess with replacing it or buying a multimeter if it’s not the likely culprit, you know? The Antec PSU tester I used shows if voltage is over or under and a general "green" if everything is OK. It shows yellow if one of the voltages is off, etc. All my lights were green (I know this is a very basic test and doesn't tell you much)!

I thought that I had a great idea by looking for a program that can log the errors and show them to you the next time you start up, but the free one I found had some scary stories attached to it. Then I found the Windows XP built in “event logger” and tried everything to get it to work and found that it won’t work in XP Home. 

I’m really looking forward to some feedback, I'm so frustrated! Thanks for listening!


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## speedster123 (Oct 18, 2006)

the 200 watt bestec is most likely the culprit.
download *speedfan*
report back your temps and voltages
did you bypass your ups and plug your computer directly into the wall socket?


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## GroverXpup (Dec 4, 2007)

Wow, thanks so much for the quick response! I downloaded SpeedFan like you suggested. I'm not sure how to interpret any of this info yet, but I' wanted to post ASAP! Keep in mind that I haven't configured anything in the program, I've done NOTHING yet but download it and open it up. Also, systems been on all day...here's what it says:

fan 1 1844 rpm
fan 2 959 rpm
fan 3 0

Speed01 46
Speed02 46
Speed03 100

temp1 34 C
temp2 -1 C
temp3 -1 C
HD0 44 C

Vscore1 1.66V
Vscore2 1.57V
+3.3V 2.58V
+5V 2.47V
+12V 13.25V

-12V -1.66V
-5V 0.27V
+5V 4.97V
Vbat 4.08


OK, please let me know what you think! Thanks again for your help


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## GroverXpup (Dec 4, 2007)

Could someone out there give me an opinion of the voltage results from Speedfan? I'm not quite sure what the ranges are for the "-" (negative)voltages! Thank you-


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## GroverXpup (Dec 4, 2007)

*Speedfan Results?*

Hello all. It was suggested that I run Speedfan and posts my results, but I haven't heard back from anyone and it's been some days! Would someone be kind enough to tell me what they think about these results? I was advised to run Speedfan because I'm trying to figure out if my PSU is the problem that is causing my PC to randomly shutdown. I explained the problem in detail in another post that I think is called "Random PC Shutdown (no reboot)." Here's what the program came up with after my PC was running (mostly idling) all day:

Thanks in advance for your help!

fan 1 1844 rpm
fan 2 959 rpm
fan 3 0

Speed01 46
Speed02 46
Speed03 100

temp1 34 C
temp2 -1 C
temp3 -1 C
HD0 44 C

Vscore1 1.66V
Vscore2 1.57V
+3.3V 2.58V
+5V 2.47V
+12V 13.25V

-12V -1.66V
-5V 0.27V
+5V 4.97V
Vbat 4.08


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## Tumbleweed36 (May 14, 2005)

We need the specs for your computer. I can tell you right now that your power supply on the +12 rail is way out of acceptable specs. Will try to get back when I see the specs so we know what you are expecting out of that power supply.

Addendum: Please don't post the same question on two threads. I have put them together and sorry no one saw your original quest for answers after you posted speedfan results.


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## GroverXpup (Dec 4, 2007)

Hello and sorry about the double post, I wasn't sure what else to do!

What specs do you need other than the "pulldown" by my username? Just let me know, I'll be more than happy to post them. Someone else suggested PC Wizard to check my temps, etc., do I posted those for you too- thank you for your help.


PC Wizard results:


Voltage CPU :	3.99 V
+3.3V Voltage :	4.08 V
+5V Voltage :	6.85 V
+12V Voltage :	15.50 V
Chassis Fan :	1939 rpm
Processor Fan :	932 rpm
Mainboard Temperature :	38 °C


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## Tumbleweed36 (May 14, 2005)

Darn, I missed the pulldown somehow, just didn't look far enough. Have you looked in the Bios to check voltages there also, because those are most generally the most reliable reading?

Anyhow, my best guess is the power supply. All the rails are way out of specs which tells me that the power supply is simply not doing the job for you with these readings. When you replace this power supply (Bestec is not a great brand and 200W is not nearly enough), please do yourself a favor and buy a decent one. If you don't plan on upgrading much on this rig, then you should be looking at a 400 watt power supply to do the job for you. We can never guarantee that this will fix the issue, because we can't physically see what is happening in that case.

If this were mine, I would go to some place like BestBuy or Stamples and purchase a decent power supply and try it. If this does not fix the issue, then take it back for a small restocking fee. If this were mine, I would get a new power supply anyhow with those readings and not take it back even if it did not fix this issue, but you have to choose what to do. When you buy (and if you buy another one), take a look at the Antec Earthwatts, Antec Trio, or even a Seasonic (higher priced) in the 400 watt range.

FYI, here is the normal operating voltage(s) of a power supply:

Power supply output range must be +/- 5%

Stated
Voltage…..Lowest……Highest.............Yours
*+12v*…,..,,,,..11.4….……12.6.............15.50 
*+5v*……..…......4.75…….…5.25 ...........6.85 
*+3.3v*…….......3.134…...3.465...........4.08
*Vcore* 

The VCore voltage is determined by the Microprocessor CORE Voltage Regulator 
Vcore – Is the operating voltage of a CPU or GPU (or other device containing a processing core.


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## GroverXpup (Dec 4, 2007)

I'm not sure how to check temps in BIOS. I can get into BIOS, but have never seen anything about temps- could you tell me how? I tried to look it up, but all I found is the suggestion to hit "delete" while booting up (to check temps in BIOS) and that didn't work- thanks for your help!


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## nunucbka (Nov 30, 2007)

Please don't try to make changes on your system before you get much more about the BIOS!

If you wanna know where BIOS is here we go:

Restart your PC, you get a black screen begin to click <Delete> until you see a bleu screen ---> you're in the BIOS!

For the temperature go to <Power> to the bottom and than <Hardware Monitor> you see the temps in �C and �F


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## GroverXpup (Dec 4, 2007)

Hi again. I know how to get into the BIOS, I don't know how to check the temps while I'm in there! I can't find anything in the BIOS that tells me anything about temps. Under Power it only asks whether or not to reboot under power failure or not-that's it. This is an older PC (2003), are you sure you can check it's temps in BIOS?


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## nunucbka (Nov 30, 2007)

yes I am 100% sure, I can check temps in my one easily...what motherboard you have?


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## GroverXpup (Dec 4, 2007)

FYI (in case anyone is interested) PC Wizard now says:

+3.3v 2.59v

+5v 2.47v

+12v 12.46


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## nunucbka (Nov 30, 2007)

sorry I dont know nothing about those voltages.. you should wait for Professional Papa's to come soon.. I am off to sleep good night man...

Good Luck !


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## GroverXpup (Dec 4, 2007)

You can see my specs in the pulldown menu by my username (for future ref). It's an ASUS A7N8X-LA. Any more thoughts?


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## Tumbleweed36 (May 14, 2005)

Tumbleweed36 said:


> Have you looked in the Bios to check voltages


 I was interested in the voltages in the Bios and not the temperatures. You had very sporatic voltages and that is what we were looking at.


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## GroverXpup (Dec 4, 2007)

I'm sorry, I don't know how to find the voltages in the BIOS. If someone will instruct me on how to do this, I'd be happy to report back...


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## Tumbleweed36 (May 14, 2005)

You need to enter the bios setup menu (usually by pressing DEL while booting), then scroll over to the POWER area on top...then scroll down to the POWER heading....then under that area, there will be VOLTAGES and TEMPS listed. Just list what it says there and you will have it. Might as well do both while you are doing them.

Note: All menu items in bios are not the same with all motherboards, but if you tool around in that area, you should find the location of those items.


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## GroverXpup (Dec 4, 2007)

I'm so sorry to be such a pain, but I can't find anything about voltages or temps in my BIOS. I've been in several times now. At the top there are different tabs. If I go to the Power tab, the only thing listed is whether or not I have it set to reboot or turn off in the event of a power failure. That is ALL that is under that tab! No mention of voltages or temps in any other tabs either (that I can find).


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## Tumbleweed36 (May 14, 2005)

Like I mentioned, each board has different options in the bios. It is not your fault if it isn't there and I suspect it isn't. I tried to download your manual but got an error, so just can't see what is there. Your's just might not have that option. 

Therefore, we need to use the data we have to make decisions. I think it is the Power Supply. YOu have to decide what action you want to take in that regard.


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## GroverXpup (Dec 4, 2007)

OK. I've suspected the PSU all along, so I might as well just take the plunge! According to HP, my PSU can only be upgraded to 400w max. So, I guess I'll read Techsupportformum.com's list of recommended ones and compare some prices. Thank you for replying so quickly today so that I can get on with this...


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## GroverXpup (Dec 4, 2007)

OK guys, here's the update. I have tested my voltages with a multimeter and they are in range...NOW WHAT? I was sure the prob was my PSU...I stressed my system with Prime95 for the last hour and voltages are staying the same or barely fluctuating (like from 4.9v to 5.0v on my +5v. My Processor activity is at 100%. What I have noticed is that my Mainboard temp (according to PC Wizard 2008) is like 72C and my HDD is like 48 or 49C right now. If you read my earlier posts in this thread, I've tried like every diagnostic I can think of to try and find out why my PC is randomly shutting down. Any more suggestions??? They would be much appreciated!


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## Tumbleweed36 (May 14, 2005)

72c is Too hot for your mainboard regardless of what you are doing. Take the side of the case off and blow a fan in there directly on the CPU and see if it shuts down on you with that fan blowing directly on there.


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## GroverXpup (Dec 4, 2007)

OK, I'll try that. Of course sometimes it works for 8 hours no prob, so it may take a while. Right now (and while Prime95 has been running), I've had my PC open, on it's side and two fans in my room on. However, I haven't tried a fan directly in it. SHould I be looking to see if the temp goes down with a fan or doesn't it matter? Are you now thinking it's not the PSU? I almost ordered one and then thought I'd check the voltages first. Does it sound to you like the PSU is OK?


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## Tumbleweed36 (May 14, 2005)

See if the fan makes the temp drop. You might very well have a power supply that is so sporatic that it causes some of these problems. However, let's look and see if we cool it down if that changes anything. I do still think your power supply is causing the shutdowns and that could also be causing heat problems. 

If you have a bestbuy or a staples, etc., nearby, then (if you wish), go there (and be sure to buy only a major brand) and buy something like the Antec Trio 650 and put it in. If that solves the issue, then keep it, and if it does not, then take it back for a small restocking fee. That way, nothing lost (except the small restocking fee) and you might gain having it work correctly.


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## speedster123 (Oct 18, 2006)

How hot is the room temperature?.. down there in Florida?

Did you change out the 200 watt bestec?


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## GroverXpup (Dec 4, 2007)

Here's the update. I tested my voltages with a Multimeter and to my surprise, this PSU is keeping very regular voltages and exactly where they should be (even under load)! So, someone suggested that I open my case and blow a fan directly in there to see if the problem could be the temps. I did this and *GUESS WHAT??? *No shutdowns in almost a week! I was waiting to write because I wanted to make sure it wasn't a fluke  So here's the thing, with an older PC like this, is it possible to get an internal fan that could possible lower the temps as well as this huge standing fan that I have aimed right at my CPU and is blowing the hell out of it? Should I just keep my PC open with the fan on it from now on (this would suck)? What do you guys suggest??? The fan is keeping my CPU at around 40 C and HDD around 42 or 43 C (just surfing the net and things like that, I'm not a gamer).

Also, believe it or not, I now have a NEW problem/question. Yesterday, I had to hook up a new PSC (All in One) printer becuase I had to put my old PSC printer somewhere else in the house. NOW when my new Epson CX9400(Fax) printer is plugged into my computer, it automatically raises my CPU temp around 15 degrees! That is when it's on "standby" or sleeping! NOW WHAT? Now when I run the fan like I was, my CPU is between 52-60 C instead of around 40 C (with the fan on it). Doesn't effect my HDD temps. If it's not one thing it's another, right? So I'm asking yet again for thoughts or comments! Thanks everyone.


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## speedster123 (Oct 18, 2006)

you need to lose the bestec and get a quality unit.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371006
if the case is lacking proper air flo, get another case, or cut a blow hole in the top with a dremal tool and exhaust fan / grill. [protecting the board, naturally]
try reading over the thermal grease instructions in my sig and consider doing a re-apply.


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## GroverXpup (Dec 4, 2007)

While I agree that the Bestec is crap, it is keeping normal voltages. Also, I need a special PSU becuase of the dimensions (micro ATX) and it's probably not possible to just go to New Egg and order one up you know? I did find a couple that would work, but nothing over 400W and not a brand like Antec (I think Athena and Logisys). Is there any way to cool the inside without drilling holes, etc. or is there no hope except for keeping the side open? And what did you think about the new problem with the temps after hooking up the Epson printer? Should I have expected to see that rise in temps or is that weird?


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