My Computer Keeps Switching Off :-(

[Daffy D]

Hi All!

I’m not having a good time these last couple of months. My computer system which has been reasonably well behaved for years seems to have acquired an infection of gremlins.

My own fault I suppose as the old saying of “If it ain’t broke don't fix it” would certainly be true in this case, but after nearly 5 years with the same system I had the uncontrollable urge to upgrade and try some of the newfangled thingies now available, ADSL, Torrents, Dual Core, DVD burners and things like that.

I’m not a bad person really but those shiny packages in the window are sooooo tempting.

So my story. My computer has acquired the nasty habit of switching off at usually the most inconvenient times. (Like there is a convenient time) This is not a “Shut-Down” as when turning off or going into hibernation but like someone pulled the plug.

It does this at random times, sometimes it will be OK for days and other times it will switch off 2 or 3 times in one day.

I have checked the obvious things, fans not working and dust in the system but that’s all fine and clean. I have also been monitoring the CPU activity and temp. The activity hardly ever exceeds 75% but most times is much lower. The CPU temp stays at the lower 40c.

The trouble started after I installed a new motherboard (ASUS P5VD2-MXSE) Dual-Core Pentium1.80GHz and new Power supply.

I thought it may be the power supply but this is rated at 400 watts well over the recommended 350 for the MB. There could of corse be a problem with the power supply but it is new so no muck build up and it has a good flow of air through it.

One point which may be relevant, when the computer switches off it will not re-start by using the start button on front of the case I have to switch off the power either at the UPS or the switch at the back of the case before it will re-start by using the start button.

I’m no electrician but this seems to indicate some sort of re-set taking place a bit like pulling the plug on UBC decoder.

Any ideas in solving this annoying problem will be greatly appreciated.

D.D.

[A_Traveller]

Does the 'glow light' remain on? On the motherboard there should be a power indicator, even if the PC is switched off showing electricity is reaching the MB? Some Asus's use a blue logo, others a small green LED.

Regards

[Daffy D]

Does the 'glow light' remain on? On the motherboard there should be a power indicator, even if the PC is switched off showing electricity is reaching the MB? Some Asus's use a blue logo, others a small green LED.

Regards

My MB has a small green LED. Silly me I never checked that light, will next time the computer switches off.

Has not done it today - yet :-)

D.D.

[Mid]

if your local , I'd suspect your electric supply .

when the local hot switching takes place here , the computer may reboot even though the TV soldiers on .

very sensitive these PC's .........................

Edited October 18, 2007 by Mid

[Daffy D]

if your local , I'd suspect your electric supply .

when the local hot switching takes place here , the computer may reboot even though the TV soldiers on .

very sensitive these PC's .........................

Had that problem with the previous MB - that would re-boot. Tried several UPS's but never cured the problem. Was hoping the new MB would solve that.

Now the problem is the computer switches off - no re-boot.

D.D.

[A_Traveller]

Daft Question, you have validated the UPS to ensure it's working? How long do the batteries give you?

Regards

[Mid]

i gave up on a brand new ups , never worked .................

my theory was that the draw on the internal ups battery was greater than the replenishing power of the local supply .

running a Thai / Chinese AVS , so far ( couple of yrs ) so good , touch wood .

[Guest Reimar]

if your local , I'd suspect your electric supply .

when the local hot switching takes place here , the computer may reboot even though the TV soldiers on .

very sensitive these PC's .........................

Had that problem with the previous MB - that would re-boot. Tried several UPS's but never cured the problem. Was hoping the new MB would solve that.

Now the problem is the computer switches off - no re-boot.

D.D.

To have the UPS working 100% you need to have grunding, to the UPS and to the Computer! If you haven't grounding, the UPS wouldn't work properly!

An "easy" test, suposed you're very "healty", stay with naked feet on the ground, not on any rubber or so and than just short touch the computer case!!

Hey, that's an joke, DON'T do that, it's dangerous!

If you have an Power- or Multimeter, check which line of your power system is + and than measure between this + line and the case. If your system is grounded it should show not more than 3 Volt but better 0 Volt! If it shows more, you haven't grounding.

Even newer MB's having problems with faulty power systems. So that is the first you really need to check.

To apply grounding is an easy Job, just go to an Hadware Store an buy an Copper Grounding pin from around 1.5 - 2 m and as much meter of cable you need, place the Pin in the soil a deep as you can (need to be in the ever wet soil) and connect the Cable between the pin and the UPS and Computer. Check the Power again as mentioned above. That's all.

If you still have problem after this, you'll need to start to check all parts of your computer seperatly!

[Daffy D]

Daft Question, you have validated the UPS to ensure it's working? How long do the batteries give you?

Regards

Yes the UPS is working. After the problems with the last system I bought an expensive one that has 2 batteries in it, a window that come up on the screen showing the state of the unit as well as a self test option.

I also pulled the plug out of the wall just to make sure it does actually work – it does. The batteries give about 15 min.

D.D.

[Daffy D]

“Reimar” - Yes I have grounding. And I so wanted to try the bare feet test

The computer is on the ground floor near a window so it was easy to run a wire and install a grounding rod.

I have everything that is connected to the computer, printer, scanner what have you running to ground.

Next question please.

D.D.

[RKASA]

Random like it is and the fact that you have to cycle the main power switch to restart it sounds like a hardware problem.  Most front panel bottons send a signal to the mother board which starts the Power supply this is because many network cards may be able to also start the PC remote.  Check that the three wires from NIC are not plugged in because it can also shutdown the PC remote and maybe it acting up.  If it keeps doing it randomly then you may have to check in to a service center.

[Pushit]

Hi All!

I’m not having a good time these last couple of months. My computer system which has been reasonably well behaved for years seems to have acquired an infection of gremlins.

My own fault I suppose as the old saying of “If it ain’t broke don't fix it” would certainly be true in this case, but after nearly 5 years with the same system I had the uncontrollable urge to upgrade and try some of the newfangled thingies now available, ADSL, Torrents, Dual Core, DVD burners and things like that.

I’m not a bad person really but those shiny packages in the window are sooooo tempting.

So my story. My computer has acquired the nasty habit of switching off at usually the most inconvenient times. (Like there is a convenient time) This is not a “Shut-Down” as when turning off or going into hibernation but like someone pulled the plug.

It does this at random times, sometimes it will be OK for days and other times it will switch off 2 or 3 times in one day.

I have checked the obvious things, fans not working and dust in the system but that’s all fine and clean. I have also been monitoring the CPU activity and temp. The activity hardly ever exceeds 75% but most times is much lower. The CPU temp stays at the lower 40c.

The trouble started after I installed a new motherboard (ASUS P5VD2-MXSE) Dual-Core Pentium1.80GHz and new Power supply.

I thought it may be the power supply but this is rated at 400 watts well over the recommended 350 for the MB. There could of corse be a problem with the power supply but it is new so no muck build up and it has a good flow of air through it.

One point which may be relevant, when the computer switches off it will not re-start by using the start button on front of the case I have to switch off the power either at the UPS or the switch at the back of the case before it will re-start by using the start button.

I’m no electrician but this seems to indicate some sort of re-set taking place a bit like pulling the plug on UBC decoder.

Any ideas in solving this annoying problem will be greatly appreciated.

D.D.

Sounds like the motherboard could have a problem, I had an Asus go down after a couple of weeks just like this computer shutting down. Go to the shop that supplied it and get them to check it out, it nshould be still under warranty.

[Daffy D]

Random like it is and the fact that you have to cycle the main power switch to restart it sounds like a hardware problem.  Most front panel bottons send a signal to the mother board which starts the Power supply this is because many network cards may be able to also start the PC remote.  Check that the three wires from NIC are not plugged in because it can also shutdown the PC remote and maybe it acting up.  If it keeps doing it randomly then you may have to check in to a service center.

Erm! what is NIC and where can I find the three wires?

We are out in the boonies with no sevice centers around besides the computer could be running for days without switch off so they would just send it back saying "No Problem"

To day it's been on for over 12 hours no problem but a few days ago it switched off 4 times in one day.

There does not seem to be any connection with what I am doing at the time. I don't play games so the computer is never "overworked"

A couple of times it switched off while I was just waiting for a page to download.

D.D.

[RKASA]

If you have a network interface card that you connect a network with (your ethernet card).  It would be the one the rj45 plug connects to looks like a phone jack only larger.  Many of these cards have three small wires with a plug that connects to the mother board.  should be black,white, and red. everything the NIC needs comes from the PCI slot so unplug the remote power control if its been plugged in. Its only a chance but could be the problem. Other wise a random problem like this can just drive one nuts.   

[Guest Reimar]

Random like it is and the fact that you have to cycle the main power switch to restart it sounds like a hardware problem. Most front panel bottons send a signal to the mother board which starts the Power supply this is because many network cards may be able to also start the PC remote. Check that the three wires from NIC are not plugged in because it can also shutdown the PC remote and maybe it acting up. If it keeps doing it randomly then you may have to check in to a service center.

Erm! what is NIC and where can I find the three wires?

We are out in the boonies with no sevice centers around besides the computer could be running for days without switch off so they would just send it back saying "No Problem"

To day it's been on for over 12 hours no problem but a few days ago it switched off 4 times in one day.

There does not seem to be any connection with what I am doing at the time. I don't play games so the computer is never "overworked"

A couple of times it switched off while I was just waiting for a page to download.

D.D.

NIC = Network Interface Card

The wire only applies for cards not for build in NIC! All the newer MB's like your one having the NIC on Board.

Have you check the Video Adapter Card? That can one of the problems!

Have you an Dialup Modem in the computer? It could be although a problem.

What's about Dust? Blow out dust from the case!

Check there is any "unwanted" connection between the MB and the Case!

I would take out everything from the Case and asseble them temporarly on an insulated surface and let them run for may several days and if the problems still occurs check part by part!

[Daffy D]

Nope! I don’t have a separate card for NIC it all came with the new MB.

“Reimar” - I did fit a Video adapter card perhaps I could take that out and run the computer without it for some time see what happens.

I have a Dial-Up Modem card fitted but most times use the ADSL External modem from TOT. Last few days have been using the Dial-Up as ADSL is down (another problem!) but the switching off problem happens/happened even when not on-line.

The computer is dust free and fans all working well.

Will take a closer look at the insides and check for any loose wires.

Thanks

D.D.

[Guest Reimar]

Nope! I don't have a separate card for NIC it all came with the new MB.

"Reimar" - I did fit a Video adapter card perhaps I could take that out and run the computer without it for some time see what happens.

I have a Dial-Up Modem card fitted but most times use the ADSL External modem from TOT. Last few days have been using the Dial-Up as ADSL is down (another problem!) but the switching off problem happens/happened even when not on-line.

The computer is dust free and fans all working well.

Will take a closer look at the insides and check for any loose wires.

Thanks

D.D.

May try to take out the Modem Card if the ADSL is working. As long as any Card is in, even if the card isn't accessed a faulty one can create problems!

[onethailand]

If the symptoms are unpredictable like you've been describing, the problem is either electrical or heat related - hardware does not normally work sometimes and not work other times.

Enough heat could cause a cracked circuit board to expand enough so that one or more of the circuits etched on the board would no longer be contiguous.

Electrical problem - grounding or no grounding, the one most vulnerable connection you have is your dial-up modem if it is an internal modem, and the telephone line is hooked up. Any surge along that line, or especially a lightning strike, can damage or destroy your computer.

[tjo o tjim]

Daffy--

Do you have the UPS itself connected to ground? Are you using serial or parallel cables at all, or is everything USB, firewire, or ethernet? Shielded cables can cause some ground loops that can be problematic. Are you using the UPS automatic shutdown software? Are you using the correct cable, or just an extra cable laying around? Is sleep mode enabled?

If all of that is working... have you done any diagnostics on the PC itself? Download one of the live CDs, check the RAM, see if anything abnormal is going on.

[ignis]

If your looking inside, take off the power supply cable on the motherboard and check it…..

I had the same problem + checked everything I could think off, last was to unplug the power supply to fit another when I noticed that one of the pins had shorted on the motherboard

When it switched itself off the blue ON light was still on but very dim.

[opalhort]

Here are my thoughts about the problem since I have experienced the same problem on different PCs in the past.

1: it can happen that when you seat the power cable plug onto the MB or other things like drives etc. that one pin in the plug may push out to the back of the plug and not connect securely. If you can see any metal poking out from the rear of the plug where the cables come out push it back in with a small tool. This solved the problem for me twice.

2: recently an old PC kept on switching of for no reason, but whenever this happened the Power supply was very hot to the touch. The cause was a USB plug from a modem which was slightly askew, probably causing a short on some pins. After re-seating the plug all was OK. In this case I also had to disconnect the power completely before being able to power up the PC in the normal way.

I have no idea if this may help you, but only speak from experience after having the same problem.

opalhort

[intumult]

When you mentioned about the external modem that reminded me.....

I had a computer shut off and also lock up on random occasions. Changed the CMOS battery 1st then, still had same problem so had the comp checked out and it was all ok. Problem lay with the modem itself. The modem was faulty and the computer would either lock up or shut down.

New modem and I no longer had a problem.

Maybe worth thinking about?

Was a long time ago and I cannot remember if it only happened when I was using the internet or not.

[Daffy D]

The electricity was out all day yesterday, happens a lot round hers, so did not get on line.

Thanks for all the useful advice and suggestions for solving my particular problem. It is difficult to solve an intermittent problem like mine and I have taken note of all the suggestions.

I double checked all the connections and the grounding as well as having a good look round the inside of the computer to check for any lose wires floating about.

I also took out the two memory module thingies cleaned the contacts and reseated them. I did the same with the graphics and the couple of other cards.

I also unplugged the main MB power supply connection, a 24 pin connector checked that out and made sure it seated back firmly.

Well fingers crossed have had no shutdowns since then, hope that this has fixed the problem. Though with all the things checked still don't know what actually caused the problem.

“intumult” – The modem or more correctly Ethernet Router was supplied by TOT when I upgraded to ADSL cant really take it back unless I’m sure it is the problem but something to keep in mind.

“opalhort” - I checked the connections as you suggested everything looked Ok but I unplugged and repluged everything so maybe that was the cure.

“ignis” - Checked the power supply to the MB connection looked good but still unplugged it sprayed it with contact cleaner and plugged it back.

“tjo o tjim” – The UPS is definaitly grounded, I don’t use UPS automatic shut down, anyway would that not shut down the computer in a civilized manner rather than just a hard switch off? I use Advanced windows care and some other “Maintenance” programs including Belarc advisor nothing shows up any problem, but then it wouldn’t as the computer is running Ok in order for the programs to work.

“onethailand” - The internal modem card is only connected to the telephone system when I am using it, when the ADSL is down. Anyway the phone line goes through a safety thing in the back of the UPS first. This also applies to the external TOT unit.

“Reimar” - As mentiond just now the internal modem card is not connected to the phone line unless I am actually using it. The shut down has happened while using ADSL with the dial-up disconnected. If all the above has not worked, and only time will tell, I'll take out the modem card and see what happens.

Again thanks to all that took the trouble to post suggestions, much appreciated.

Thank Y’all

D.D.

[silverhawk_usa]

The electricity was out all day yesterday, happens a lot round hers, so did not get on line.

Thanks for all the useful advice and suggestions for solving my particular problem. It is difficult to solve an intermittent problem like mine and I have taken note of all the suggestions.

I double checked all the connections and the grounding as well as having a good look round the inside of the computer to check for any lose wires floating about.

I also took out the two memory module thingies cleaned the contacts and reseated them. I did the same with the graphics and the couple of other cards.

I also unplugged the main MB power supply connection, a 24 pin connector checked that out and made sure it seated back firmly.

Well fingers crossed have had no shutdowns since then, hope that this has fixed the problem. Though with all the things checked still don't know what actually caused the problem.

“intumult” – The modem or more correctly Ethernet Router was supplied by TOT when I upgraded to ADSL cant really take it back unless I’m sure it is the problem but something to keep in mind.

“opalhort” - I checked the connections as you suggested everything looked Ok but I unplugged and repluged everything so maybe that was the cure.

“ignis” - Checked the power supply to the MB connection looked good but still unplugged it sprayed it with contact cleaner and plugged it back.

“tjo o tjim” – The UPS is definaitly grounded, I don’t use UPS automatic shut down, anyway would that not shut down the computer in a civilized manner rather than just a hard switch off? I use Advanced windows care and some other “Maintenance” programs including Belarc advisor nothing shows up any problem, but then it wouldn’t as the computer is running Ok in order for the programs to work.

“onethailand” - The internal modem card is only connected to the telephone system when I am using it, when the ADSL is down. Anyway the phone line goes through a safety thing in the back of the UPS first. This also applies to the external TOT unit.

“Reimar” - As mentiond just now the internal modem card is not connected to the phone line unless I am actually using it. The shut down has happened while using ADSL with the dial-up disconnected. If all the above has not worked, and only time will tell, I'll take out the modem card and see what happens.

Again thanks to all that took the trouble to post suggestions, much appreciated.

Thank Y’all

D.D.

All the above seem to be more knowledgeable than I, but a personal experience just for reference;

I had a Toshiba laptop that kept cutting out similar to your experience. After checking many things the factory finally admitted there was a problem and later released an updated Bios for this model. No idea what was changed, but could there be some type of incompatibility with some of the changes you made? Can you upgrade or change the bios? Just throwing this experience out for thought. My computer knowledge is not that great. Hope you solved the problem already.

[Daffy D]

UPDATE

Thought I had it licked, the computer was running fine for a couple of days then without warning it switched off again.

Desperation was setting in.

I pulled out the video and modem card so now only the mother board was active

“Silverhawk” - I figured how to update the BIOS (surprised the h*ll out me when that actually worked).

This worked fine for several days and then yesterday it switched it’s self of twice in one day.

Now I have connected a different UPS (from the TV/UBC) and also pulled out one of the two memory RAM thingies. I got 2 memory slots with 1Gig in each.

Hope this solves the problem as I have no idea what to do if this does not work.

In answer to “Traveller” when the computer switched off the green LED on the motherboard is still alight, don’t know if this is significant.

Thanks to everyone for their input.

D.D.

[A_Traveller]

If the LED on the mother-board is on, then forgive stating the obvious, the MB is at that time receiving power. If there is no evidence of power outage from other kit connected to the UPS {or signal form the UPS of failure} then, in my view, it would point to either the PSU or the MB itself.

Regards

[Daffy D]

If the LED on the mother-board is on, then forgive stating the obvious, the MB is at that time receiving power. If there is no evidence of power outage from other kit connected to the UPS {or signal form the UPS of failure} then, in my view, it would point to either the PSU or the MB itself.

Regards

This is the problem. When the computer switches off for all practical purposes it’s OFF.

The fans stop, I presume also the drives as the sudden silence is deafening there is no green (on) light on the front panel and no HDD activity light and the monitor goes blank.

The UPS is still active, normal lights on, but as I said in the OP I can’t switch on again by the front panel start button I have to switch off/on the power either from the UPS or from the switch at the back of the case.

I’m thinking it has to be the MB as there is not much left in the box right now – but where to look?

D.D.

[onethailand]

As I mentioned before, it's possible your MB has a crack somewhere. It is difficult to detect without a magnifying glass and you'd have to pull the board out of the computer anyhow.

If it's still under warranty, I would take it back to where you bought it and ask them to test and/or replace the MB.

[oimatchi]

This might not work for you but might be worth a shot.

I once had some similar symptoms, my computer just shut off by itself constantly.

My problem was caused by Spylock, a virus. Nothing could find it.

The only way I could fix it was to reboot in safe (with standard non USB keyboard, doesn't work with those) and then run AGV spyware scan.

That fixed it.

[Thanh-BKK]

Hello.

If a VIRUS causes a machine to shut down, it will, under any circumstances, power up again when the "Power" button is pressed.

To the OP: Go to Panthip and buy a new power supply. Doesn't matter which one, a cheap no-name will do (300 Baht). Back at home, hook that up to your mainboard and any drives that you have in the machine. Test it. See if your machine shuts down again. My guess is: It will NOT shut down.

If so, go to Panthip again. Sell the power supply that you bought for 100 Baht at some place that sells second-hand parts, and then go shopping. Look for a power supply brand ENERMAX, and take one no less than 450 watts. Take the version with DUAL FANS. Yes, it will cost you 3.000+ Baht. DO NOT KEEP YOUR MACHINE EQUIPPED WITH THE CHEAP ONE YOU GOT ONLY FOR THIS TEST!!!

But with Enermax that your computer WILL work, and will do so for many years to come.

What you have right now is a power supply that says "400 watts" on the sticker, but if it were tested by someone with apropriate equipment you would see that it would output maybe 300 watts. The voltage drops when there is load - you may see 11.2 volts where there are supposed to be 12 volts, and you will see 4.5 volts where there are supposed to be 5.0 volts.

Your system most likely draws more power than your power supply can supply, and if some application demands even more (something graphics-intensive will get the graphics card to draw more, something that demands a lot of CPU power will cause THAT to draw more, and if you burn a CD or DVD this will cause the burner to draw more - and your power supply will just do what it is supposed to do - shut off. It may shut off only the 12V circuit, or the 5V circuit, or the 3.3V circuit - in any case your computer will immediately go dead. And you need to remove power completely (pull plug or switch off UPS) to "reset" this protective mechanism in the power supply.

Believe someone with knowledge on power supplies. There is a reason why some power supplies "550 watts" cost 300 Baht while others rated "460 watts" cost 3.000 Baht. And i fixed plenty computers that were FRIED by failing cheap power supplies (hint: What comes in a PC case when you buy it is crap).

Best regards.....

Thanh

By the way i have a UPS brand "Leonics", no grounding in my room (and no option - 6th floor, would need a lot of wire to run my own grounding....) and it still works flawless, and i get NO shocks when touching the case thanks to the UPS which completely seperates anything connected to it from the actual main power.

Edited October 29, 2007 by Thanh-BKK