Computer power supply failure

#juan

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Aug 30, 2005
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The power supply on my wife's computer just died and in dying it wiped out the memory and may have damaged the motherboard or the CPU. Has anyone heard of this before?
 

gerryh

Time Out
Nov 21, 2004
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The power supply on my wife's computer just died and in dying it wiped out the memory and may have damaged the motherboard or the CPU. Has anyone heard of this before?


Never....unless we are talking about a power spike that took out the powersupply and also other components.
 

#juan

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Aug 30, 2005
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This is a copy and paste I just found:

How to Diagnose and Replace a Failed PC Power Supply

When a PC power supply dies or begins to wear out, it must be replaced. With a few simple tools and the help of this guide, you can do this job yourself and save on expensive repair fees.
[edit] Steps

  1. Familiarize yourself with proper ESD procedures before doing any kind of PC repair work which requires opening a computer. If you neglect this step, you may damage your computer.
  2. Verify that the power supply needs replacement. The most obvious clue is that the system will do absolutely nothing when you hit the power button. If there is no sound and no monitor activity of any kind, the power supply has probably died. While this can also be caused by a faulty switch, it is usually the result of a burned-out power supply. To verify it is not the motherboard giving the problems, take a paper clip and insert it into the green and black terminals of the power supply plug after it is removed from the motherboard of the computer. Press the power button on the computer, if the fan spins inside the power supply, the motherboard is the problem. If the fan does not spin the power supply is dead. Another obvious clue is smoke or an odor of burning electronics, which will often (but not always) be noticed in a system that does absolutely nothing when you try to start it up.
  3. Once you are satisfied that the power supply is the culprit, disconnect all external connectors (including the power cord) from the machine. This may include keyboard, mouse, network cable, speakers, etc.
  4. Remove the case cover, placing any screws somewhere where they will not get lost.

  5. Identify the power supply unit. It will be connected to almost every component inside the computer case and will look something like this:
  6. Using proper anti-ESD practices, disconnect all connectors which run from the power supply to the devices inside your PC.
  7. Unscrew the mounting screws on the back of the case which hold the power supply in its housing. Place the screws in a handy location.
  8. Gently remove the old power supply from the case. This is usually a simple process, but if there is very little room in your PC, it may be necessary to remove other components in order to get the power supply out. If you don't feel comfortable removing other components, replace the mounting screws and enlist the help of a PC expert before continuing. Do not try to yank a power supply out by force.
  9. Purchase a new power supply of the same type as the old one. Most power supplies used in modern computers are of the "ATX" variety, but if you aren't sure, take the old unit to the store with you to compare. The simplest rule of thumb is that the new unit should be exactly the same width as the old one. It's fine if the new unit is a bit longer, as long as it will still fit into your case. Do not hesitate to ask the salesperson or technician for help in identifying the correct unit to purchase.
  10. Unpack the new power supply and make sure it physically fits correctly. If the new unit has a large bottom mounted fan, the bottom rear bottom flange on some cases might get in the way. Add it to the case in the same place the old unit was, and use the mounting screws to fasten it down.
  11. Using proper ESD procedures, connect the devices in your PC to the new power supply. The connections should be the same as they were before. It can require a bit of force to insert power connectors correctly, but if if you have to strain a great deal to push them in, you may be trying to connect them backward. It is very difficult to connect most Molex connectors improperly, but if you are determined (and strong) enough, it can be done. If you have to force too hard, try turning the connector around.
  12. Verify that no cables or unused connectors are stuck in the CPU fan or touching other moving parts. If the CPU fan is stopped by a loose connector (or any other obstruction), the processor can be destroyed very quickly. You may wish to restrain unused cables to prevent them from getting tangled up in fans.
  13. Replace and fasten down the case cover.
  14. Replace all external connections to the back of the computer (power cord, mouse, keyboard, monitor, network cable, speakers, etc).
  15. Power up the system and enjoy.
  16. If your system doesn't start up correctly here, your failing power supply could have taken out the motherboard.


[edit] Tips

  • If you suspect that your power supply is dying, replace it. A common clue which indicates a failing power supply is a high-pitched whining or grinding noise from the area of the case where the power supply is housed. Don't wait until the supply dies, because its failure can cause voltage problems which can ruin your motherboard, hard drive, or other components.
  • Invest in a high quality power supply. Do some research before you purchase one. More wattage on the package doesn't mean better. Most home PCs don't actually use more than 300W even though this is not what power supply marketing people want you to know. The unit should provide adequate wattage for your needs. Don't skimp on the power supply, as you may regret it later. Power supplies that fail can damage other components in your computer, especially the motherboard.


[edit] Warnings

  • If it's hard to remove a hard drive or CD/DVD drive power connectors, don't pull on it hard. It will come out suddenly and you'll likely cut your hand on sharp edges. Wiggle gently as you pull out.
  • Don't attempt to open a power supply unit to attempt repairs or experiment with the parts if you're not familiar with working with high voltage circuits. The primary side of power supply operates around 340V DC. Power supplies contain capacitors which can hold dangerous charge for a few minutes. Usually the integral bleeder resistor ensures the capacitor does not remain charged for much longer than a few minutes. Most problems are not repairable by the home user. Refer the unit to a qualified electrician, or better yet, recycle it and replace it with a new or refurbished one as described here. The cost of having a power supply repaired is often more than the cost of a replacement unit.
  • Sometimes, a failing power supply can continue to boot the system, causing only minor lockups and shutdowns. If this is the case, you should try to rule out other problems before replacing the power supply. While it is always best to replace a power supply you have good reason to believe is faulty, you should be sure that the problem is not caused by other factors.
  • Do not do this on Dell Computers! Some Dell computers are designed to use an odd connector. If you use a standard power supply you may damage the power supply, the motherboard or both! This also goes for Compaq, some HP and other brand-name PCs. Check first!
 

gerryh

Time Out
Nov 21, 2004
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ok Juan, why do you think it's the power supply, and why do you think the memory and/or MB is cooked?
 

#juan

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Aug 30, 2005
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First of all, the computer wouldn't boot up. Secondly, both RAM cards were dead.(tried them in another computer) Thirdly, with a new power supply and new RAM, the computer booted up right away. There are still some anomalies in the way the computer operates that make me suspicious that maybe the MB was not completely untouched.
 

gerryh

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Nov 21, 2004
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Then I would say a power spike was probably the culprit. With the new system, and any other electronics you have, may I suggest a good quality power bar with surge suppression. Considering where you live, it might be an idea to look at new breakers that can take care of suppression and also will "clean" the power to that circuit. Can end up saving not only computers but electronic appliances, T.V., and stereos.
 

thomaska

Council Member
May 24, 2006
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Great Satan
Can static discharges do something this bad to a computer?

Oh, and by the way this has been the most useful thread on the front page today.
 

gerryh

Time Out
Nov 21, 2004
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Can static discharges do something this bad to a computer?

Oh, and by the way this has been the most useful thread on the front page today.


Static discharge can cook a memory stick.....screw up a hard drive..... screw up a MB....I haven't heard of anyone screwing up a power supply with a static discharge.
 

DurkaDurka

Internet Lawyer
Mar 15, 2006
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Toronto
The power supply on my wife's computer just died and in dying it wiped out the memory and may have damaged the motherboard or the CPU. Has anyone heard of this before?

Anything can go when a power supply dies, especially if it dying resuults in a huge surge.

Power supplies are one of the most important pieces of a computer but a commmonly overlooked piece.

The power supply units that come with OEM PC's are usually on the low end of quality. I highly suggest you purchase a PSU by Antec, Silverstone, PC Power and Cooling.
 

#juan

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Aug 30, 2005
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Static discharge can cook a memory stick.....screw up a hard drive..... screw up a MB....I haven't heard of anyone screwing up a power supply with a static discharge.

I think you are missing the point Gerry. The PSU can give a voltage surge when it dies and that is what will kill other components like the memory, the motherboard, the hard drive, etc.
 

gerryh

Time Out
Nov 21, 2004
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Sorry...I have yet to see that happen....and I have replaced ALOT of dead or dieing PSU's.
 

#juan

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Aug 30, 2005
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Anything can go when a power supply dies, especially if it dying resuults in a huge surge.

Power supplies are one of the most important pieces of a computer but a commmonly overlooked piece.

The power supply units that come with OEM PC's are usually on the low end of quality. I highly suggest you purchase a PSU by Antec, Silverstone, PC Power and Cooling.

Thanks Durka
My wife said there was a small puff of smoke and a burning smell from the power supply unit(back of the tower case at least) when it failed. Didn't find out about the other components untill later.
 

DurkaDurka

Internet Lawyer
Mar 15, 2006
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Thanks Durka
My wife said there was a small puff of smoke and a burning smell from the power supply unit(back of the tower case at least) when it failed. Didn't find out about the other components untill later.

That sucks Juan :(

Before declaring the motherboard to be dead, try taking off the CMOS battery for a few minutes, put it back in and boot up.
 

MikeyDB

House Member
Jun 9, 2006
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If you live in areas prone to electrical anomalies (surges, low-voltage etc.) and your computer is critical to your business/enterprise (or you don't perform regular back-ups) I'd suggest investing in a UPS system. Make sure that the unit you're looking at has line filtering and conditioning, as well, units that are "full-time" as opposed to swiched into line when a power condition outside the norm are sensed. These units (I was a dealer for American Power Conversions and Triplite (don't know if these units are still around...) but the stand-bys that are switched into circuit last longer (battery life) than do the "full-time" variety, but the added expense of the full-time units even with battery replacement assures you of significantly greater assurance from all aberrant line conditions than do the switched variety. Now it's been a while since I researched this hardware so my info is suspect... How about it Durka...had any up-close and personal experience with UPS/s? :)
 

DurkaDurka

Internet Lawyer
Mar 15, 2006
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Toronto
You can never go wrong with a UPS, provided you have the know-how to hook one up. I personally don't use one at home, as I live like to live life dangerously ;)

At my work, we have redundant power to all the servers and backup generators in case the power ever goes out for a significant amount of time. The porn servers need their juice, otherwise there might be some sort of uprising in our subscriber base.
 

#juan

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Aug 30, 2005
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We lived on Gabriola Island for over seven years. We must have lived a charmed life during that time because we had power outages at least once a week, sometimes three or four times a week. Once the power went on and off several times in a matter of seconds. I had to re-install Windows but nothing else was damaged. Power surges and outages were fairly common on the island but hard drives were the only thing that seemed to be effected. Went through about a dozen hard drives in the seven years
 

Graywolves

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Apr 26, 2009
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Though this has been here a while...cannot hurt to add a comment.

If you are not sure the PSU has been damaged, use a diagnostics program like SiSoft Sandra. It has an environment monitor which you can use to review the running condition of your hardware, in this case, voltages and temperatures. Depending on your PC's internal monitoring capabilities, you should be able to determine quickly if the PSU is failing.

I recently repaird the parents PC after some supposed tech told them their mainboard was damaged. They consulted me after discovering just how much that would cost...mainboard, memory, CPU and vid card all would have to be done, which is costly. Pain in the ass when old hardware just is not available NEW off the shelf...I don't trust second hand hardware.

I am an electronics engineer by training, and the parents wanted my opinion. After taking an initial look, and wasting time replacing the caps (which the other tech was blaming the cause of the failure to POST), I was able to get the PC limping into the OS. Sisoft Sandra revealed a very eratic +5V standby voltage...as low as 1.5v up to 7 volts. Also, an intermittant hard drive failure at boot time was being reported, and SiSoft revealed that problem to be due to the +12V rail not up to par...it was averaging 11.2 volts with a registered low of 10.8V, well outside the 5% tolerance of most mainboards.

Though I do not blame a power surge, I do suspect the PSU simply had taken enough and could no longer hold it up. Newer components since the PC was put together, additional stuff as well...there are limits.

As for the comments about surge protection, I highly recommend a power conditioner. Surge protection devices are very limited in design and what they can do, and many do not survive a serious overload situation. It is mainly due to the varistors placed inside...they have a maximum voltage resistance...exceed that and it damages the device irreparably. Replace the power bar is the case.

A power conditioner on the other hand, is an active device that takes the AC power and through several different components, filters out surges and sags, essentially outputting a clean AC signal. It typically is not replaced like a basic power bar is, primarily because of the multiple components inside which are designed to take the punishment. They are costly, but are an essential device for places where power is not clean. Machine shops, welding shops, garages...construction areas...anywhere you need to have a PC (or photocopier which is primarily where I am familiar with them) is required to be reliably running.

A UPS is similar, but is a bit overkill in the price tag and size for a simple PC that doesn't require that much but is still in a problem zone.
 

Nuggler

kind and gentle
Feb 27, 2006
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Backwater, Ontario.
The power supply on my wife's computer just died and in dying it wiped out the memory and may have damaged the motherboard or the CPU. Has anyone heard of this before?


Yes. Guess the old power supply just wore out. We bought a new "power box", installed it, and now everything is ok, except the memory is somewhat reduced. Working on that.

Get a smart son in law to fix it. The place I bought it from tried to rip a 1 foot section of skin from my back. So far, I have my skin, and the computer's up and running.

Good luck.

;-)


Keeerist!! Another blast from the past............wish they'd quit with this. Or I"d learn to read dates.