# Frustrating PSU failures



## DaveC (May 26, 2005)

Issue:
 - Constant PSU Failures. Only solution is to replace the PSU which is only a temporary solution.

Symtpoms:
 - PC receives no power.
 - No spin-ups or system initialization of any kind.
 - No lights or visual cues of any sort.
 - No audio or audible cues whatsoever.
 - Replacement PSUs last no longer than 1-7 days.
 - Most PSUs die silently and on some rare instances have actually sparked (aka shorted).

Resolution Steps:
 - Professional diagnostics of PC revealing no issues other than a dead power supply as per two seperate technicians.
 - Power supply replaced. Diagnostics performed for a second time by two seperate technicians.
 - Custom hardware components removed.
 - All hardware components removed aside from RAM, Main HDD, and built-in components.
 - PSU replaced several times more. (Both generic and name brand PSUs have been used ranging from 250W - 500W). (And Praetor's article was studied and put to good use - I assure you.)
 - Power protection equipment replaced.
 - Electrical outlets and wiring tested.
 - Fuses replaced inside power supply (an obvious failure but worth a try - and a wonderful fireworks display after I discovered I was still alive).

History of Technical Issues:
 - Audio chipset built into motherboard died. No indication as to why. Diagnostics from techs stated that it had simply "burned out". Replaced with the Creative Labs Sound Blaster audio card.

EMACHINES (OEM) Desktop PC
Model #: T2792
Rating: 100-127/200-240V 60/50Hz, 6.0/3.0A

Specifications:
 - Microsoft® Windows® XP Home Edition
 - Intel® Celeron® 2.70 GHz Processor 128KB L2 cache & 400 MHz FSB
 - Intel® 845GV Chipset
 - 256 MB DDR (PC 2100)
 - 80 GB HDD 1
 - 48x Max. CD-RW/DVD Combo Drive; 3.5" 1.44MB FDD
 - Intel® Extreme Graphics 3D 64MB Shared Memory
 - 10/100Mbps built-in Ethernet
 - 56K ITU v.92 ready Fax/Modem
 - AC '97 Audio
 - Standard Multimedia Keyboard, 2-Button Wheel Mouse, Standard Stereo Speakers
 - 6 USB 2.0 ports (2 on front), 1 Serial, 1 Parallel, 2 PS/2, Audio-In & Out

Reference:
http://www.emachines.com/support/product_support.html?cat=desktop&subcat=T-Series&model=T2792

Further Details:
 - Memory: MEM,DDR-RAM 256MB (Max. 2GB) 	
 - FDD Model: FDD, SFD-321B/LTGNQ
 - HDD: HDD, 80G 7200rpm
 - Power Supply: PS, 250 WATT
 - Speaker:	SPEAKER, SP-20A
 - CPU Fan Type: FAN,H/S CEL-P4 2.8
 - MB: MB,IMPERIAL GV
 - Modem: MODEM,CONEXANT FAX/MODEM 56K V.92 	
 - Mouse: MOUSE,SILVER 3 BUTTON WHEEL
 - ODD1: COMBO,CDRW(48X24X48)/DVD(16X)
 - Keyboard Model: KB, PREMIUM BLACK KB-0108,PS/2 PORT
 - Chassis: BEZEL, NEXGEN-2 MAIN CHASSIS FRAME
 - CPU: CPU,CELERON 2.7GHZ 478P 128k F400
 - Video: Video, integrated
 - LAN: LAN, 10/100 integrated

Reference:
http://parts.emachines.com/emachines/sys_lookup.asp

Custom Enhancements:
 - Creative Labs Sound Blaster Audigy 2 ZS 24-Bit Audio Card
 - Seagate 20 GB HDD (Model #: ST320410A)
 - Logitech Elite Keyboard (Model #: 967234-0403)
 - Logitech QuickCam Messenger (Model #: 961237-0403)

And just for laughs...

Number of PSUs Burned:
9 (Something else is wrong, you think?)

Estimated Amount Spent in Repairs:
$650 USD (The price of a new PC)

Amount Spent Purchasing PC:
$899 USD

Realizing I am not technically inclined:
Priceless.

Now, *sigh* any suggestions? Just looking for feedback. And because the techs whom I paid good money too seemed to be clueless on this issue as well, be sure to think outside-the-box at issues that might not be hardware related at all. Also, I've provided all the information I can think to include. If further info is needed, let me know.

Even after having spent the money I have on repairs, I would still like to see it running normally. Due to the unfortunate incident known as the "US Economy" and other financial responsibilities, finding a huge wad of cash to simply buy a new PC altogether will be difficult. And I would like to fully understand the issue this PC is suffering before I go purchase a decent PC and bring it home to a potentially fatal and similar situation.


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## evilxp2800 (May 26, 2005)

Nice ....


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## randruff (May 26, 2005)

Check this out....I went through 3 psu's in a week once.....the culprit? A screw was lodged perfectly underneath my mobo, somehow not frying the mobo, but killing the psu. I highly suggest taking out the mobo and waiting for a little screw to fall to the bottom of the case as you unscrew the last mount. Sounds to me like this is EXACTLY what you have going on.


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## DaveC (May 26, 2005)

An excellent suggestion. However, I had thought that it might be some sort of insect or obstruction casing the issue and have already taken the entire PC apart and had it professionally cleaned. This unfortunately doesn't seem to be the issue.


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## randruff (May 26, 2005)

Hmmmmm.....now i really am almost out of suggestions. My last guess would be instabilty in the current flow from your outlet. I know you said you had it tested but i have no idea what else it could be. Granted, I am not proficient in this area, but that would be my guess. Any other suggestions guys?

one more thing....The small mounts that lie underneath the mobo...the mounts that you screw the small screws into to hold the mobo in place....possible a design flaw in the mobo, touching those metal mounts, is causing the psu to go? i have had a computer, right after a build, not start because of that....now i put electric tape over each mount and poke a little hole in it.....i dunno, prolly an irrelevant suggestion.


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## DaveC (May 26, 2005)

That too was an excellent suggestion and I appreciate all of your input on this matter. But I thought of that too. 

I'm more concerned with the fact that on 2 of the occassions, the power supply basically exploded. At least it sparked and the distinctive odor of fried electronics started eminating from the ventilation holes on the power supply.

After the last PSU death I had the PC again tested. Seems all of my components are in good working order still (thank God for that) and I simply need to replace the power supply.

In thinking about other possible causes I recalled having trouble with my DVD/CD-RW combo drive. In fact, I am fairly sure that it too has failed. But that was before the power supply issues (though it is still possible that it was a sign of the problems to come). 

I think that, just as a form of experimentation, I should invest in another decent power supply and a new CPU fan. From what I am hearing, a dying fan can cause tons of havoc with the PSU and eventually the other components. And thinking back even further, I do remember random restarts (though not very frequent) and complete lock ups which might indicate that the fan is failing and not doing its job of cooling the system. And though this might not be much help, the side panel of the system was usually left off when I started noticing those issues which, like I said, I contributed to overheating.

But getting back on track, I think an excellent test would be to buy a dependable but not overly expensive power supply and CPU fan and then send the system over to a buddy's house and have him run it 24/7 for a week or two to see if the same issue occurs.

If so, at least that rules out electrical issues and I will only be out another 30-40 bucks for the power supply. But that beats spending money on all new hardware components if I don't have to. If not, I guess I will be spending more money on refurbing the other devices, and I will at least have time to fumigate the apartment while I wait for the results. (I'm paranoid, sorry.)


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## Praetor (May 27, 2005)

*First and foremost*: Wow. Finally someone who thoroughly asks a question. Havnt seen that for a looong looong time. Major respect for that  Now onto a solution.



> Replacement PSUs last no longer than 1-7 days.


1. Do they work on other machines or do they fail entirely
2. What make and model of PSUs have you purchased?



> However, I had thought that it might be some sort of insect or obstruction casing the issue and have already taken the entire PC apart and had it professionally cleaned


Good call, i would suggest still that you assemble the computer outside of the case (i.e., on a table or something) to remove any remote possibility of "stuff getting out of place" when reassembling etc


Furthermore, look into a program like speedfan or mbm5 to monitor your voltages ... are they stable? (i.e., do they fall within parameters). Also have a look at *PSU 101*.
 to determine (for yourself) if your PSU is a good one or not




> PSU replaced several times more. (Both generic and name brand PSUs have been used ranging from 250W - 500W). (And Praetor's article was studied and put to good use - I assure you.)


Well seems you've beaten me to it


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## randruff (May 27, 2005)

I am honestly clueless! Praetor, its pretty evident you know your stuff. With that said, i guess i have a question for you that would relate to DaveC's prob....You mentioned monitoring the voltages.....am i wrong in assuming the psu controls the voltages? If that is the case, wouldnt that rule out the psu since so many have fried? Just another friendly suggestion, tryin to help this guy out.....


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## DaveC (May 27, 2005)

Praetor said:
			
		

> 1. Do they work on other machines or do they fail entirely
> 2. What make and model of PSUs have you purchased?
> 
> 
> ...



The power supplies have ranged from cheap to expensive and the specifications have varied but always exceeded what I needed. I can't even begin to tell you all of the brands. Hipro was the last make, and the only other manufacturer I can think of right now is Allied. I try not to keep junk laying about. Though I should have kept them now that I think about it.

MBM5 was partially installed before I got frustrated and decided to give up on it (I am definitely not a hardware guy). Once the power supply is reinstalled along with a new CPU fan and fan filter I will install MBM5 with the assistance of my buddy and have him monitor it. He has gladly agreed to do so.

And as we speak, I am again cleaning all of the components and reinstalling them. Afterwards, when I find some extra cash in a few days, I will be adding the PSU again and go from there.

So... We'll see what happens.


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## randruff (May 27, 2005)

best of luck buddy!


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## Praetor (May 27, 2005)

> the mounts that you screw the small screws into to hold the mobo in place....possible a design flaw in the mobo, touching those metal mounts, is causing the psu to go


Generally you have paper-washers to avoid that but even without those you should be ok since there is usually a 2mm buffer zone around the holes. Again to rule out this possibility, assemble the computer in its basic state (processor, ram, video, power) on a table or something



> From what I am hearing, a dying fan can cause tons of havoc with the PSU and eventually the other components. And thinking back even further


A dying CPU fan generally only affects the CPU rather than anything else.



> In thinking about other possible causes I recalled having trouble with my DVD/CD-RW combo drive. In fact, I am fairly sure that it too has failed. But that was before the power supply issues (though it is still possible that it was a sign of the problems to come).


Make and model of the optical drive? I explain how to find out all the gooey information here (or at least I think I did hehe)



> You mentioned monitoring the voltages.....am I wrong in assuming the psu controls the voltages?


1. Some PSUs allow for their voltage levels to be tweaked (i.e., most if not all of the PSUs in the very last category of reccomended PSUs in my 101)
2. Im no electrician but intuitively (although this may be getting into semantics), to say the "PSU controls the voltages" might be slightly off: the components of the computer (i.e., the motherboard and the major hardware connected to it) draws _power_ (in the form of current rather than voltage) and the PSU attempts to provide the appropriate current levels for the various voltage levels. The voltage levels are hardcoded (±3.3, ±5 and ±12 volts). In an ideal world the voltages are delivered as 3.33333333333, 5.0000000000 and 12.00000000 volts although we dont live in that world. It's not a huge leap of faith to suggest that a cheapo PSU is going to be significantly more inaccurate than a more premium one.
3. The ATX specification requires that the ±3.3 and ±5 volt rails remain in a ±5% tolerance spectrum and the ±12v rail remains within 5-10% (10% during maximum load). 



> Hipro was the last make, and the only other manufacturer I can think of right now is Allied.


Objectively, neither brand strikes me as being anything spectacular: I dont mean the wattage but rather the reputation for stable voltages and such. Just a check: you are running 115V right? "Several days" seems a bit long for accidentally having the PSU on the wrong setting but ya never know.

A few things to consider:
1. Could it be that power is bad in your neighborhood? In that floor/house/room/outlet? One way to somewhat rule out that as being a possibility is to get a UPS (and possibly return later although its a hell of an investment) to clean up the power. 
2. Can you do a CPUz register dump and attach the file? I explain how to do so here
3. If you cant get MBM5 working, use Speedfan, much more straightforward (although I dont know if it has extended logging capacity, i dont use it)
4. Whats the ambient room temperature? PSUs become less and less efficient as the temperatures go up.
5. As a test, turn the computer off for some time (an hour or so -- so that the PSU cools down), when you turn it on, go straight to the BIOS and note all the voltages (if your BIOS lets you). Then let your computer idle for about 20 minutes doing nothing and start your voltage logging ... once you have an idea how the voltages are during an 'idle' state, you may consider benchmarking your system (Prime95 works well although it generates a lot of heat, make sure your system can handle that too) and keep an eye on the voltages.
6. The onboard audio "simply dying" could be an indication that this may be a two prong problem: both the PSU and possibly the power regulation on the motherboard could be faulty (check your mobo visually for popped capacitors)


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## randruff (May 27, 2005)

ahem....ummm......what he said hahaha


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## DaveC (May 28, 2005)

Praetor said:
			
		

> Generally you have paper-washers to avoid that but even without those you should be ok since there is usually a 2mm buffer zone around the holes. Again to rule out this possibility, assemble the computer in its basic state (processor, ram, video, power) on a table or somethin


 
3mm buffer zone and paper washers. Already assembled on the table. Proper measures taken for grounding and so on. 



			
				Praetor said:
			
		

> A dying CPU fan generally only affects the CPU rather than anything else.


 

I should still replace it anyways. It's not a big expense. I was thinking that perhaps a dusty dying fan might cause it. I read it on another article somewhere. I will have to check my history later. But its good to replace the fan and add some dust filters to be safe just for the issue of overheating if that is what it might be.



			
				Praetor said:
			
		

> Make and model of the optical drive? I explain how to find out all the gooey information here (or at least I think I did hehe)


 
I'll take a look at it when I get home (currently at work) but as i mentioned, after the 3rd power supply i stopped using everything aside from the single HDD and RAM. No other components were installed. Wouldn't that rule out the optical drive? I mean.. It's sitting in a pile in the corner of the room in no way attached to the PC.



			
				Praetor said:
			
		

> 1. Some PSUs allow for their voltage levels to be tweaked (i.e., most if not all of the PSUs in the very last category of reccomended PSUs in my 101)
> 2. Im no electrician but intuitively (although this may be getting into semantics), to say the "PSU controls the voltages" might be slightly off: the components of the computer (i.e., the motherboard and the major hardware connected to it) draws _power_ (in the form of current rather than voltage) and the PSU attempts to provide the appropriate current levels for the various voltage levels. The voltage levels are hardcoded (±3.3, ±5 and ±12 volts). In an ideal world the voltages are delivered as 3.33333333333, 5.0000000000 and 12.00000000 volts although we dont live in that world. It's not a huge leap of faith to suggest that a cheapo PSU is going to be significantly more inaccurate than a more premium one.
> 3. The ATX specification requires that the ±3.3 and ±5 volt rails remain in a ±5% tolerance spectrum and the ±12v rail remains within 5-10% (10% during maximum load).


 
I was looking into getting the OCZ PowerStream you recommended once the issue is resolved or at least figured out. What sort of devices would you recommend as far as preventing the power supply from exploding again? Some sort of power related hardware I mean. I have already invested about 100 bucks on a really good surge supressor. What else is available for issues like this?



			
				Praetor said:
			
		

> Objectively, neither brand strikes me as being anything spectacular: I dont mean the wattage but rather the reputation for stable voltages and such. Just a check: you are running 115V right? "Several days" seems a bit long for accidentally having the PSU on the wrong setting but ya never know.


 
115V as you assumed. And after that many PSUs, you tell me how you would feel shelling out the money for a really good PSU knowing it could last less than a day. 



			
				Praetor said:
			
		

> A few things to consider:
> 1. Could it be that power is bad in your neighborhood? In that floor/house/room/outlet? One way to somewhat rule out that as being a possibility is to get a UPS (and possibly return later although its a hell of an investment) to clean up the power.


 
Its definitely a possibility. The apartment I ive in isn't exactly the Ritz. It was built in the 60s. Which was the purpose of purchasing all the power hardware.



			
				Praetor said:
			
		

> 2. Can you do a CPUz register dump and attach the file? I explain how to do so here


 
Still waiting on the extra cash. But I will look into it when I get the PC powered up again.



			
				Praetor said:
			
		

> 3. If you cant get MBM5 working, use Speedfan, much more straightforward (although I dont know if it has extended logging capacity, i dont use it)


 
I'll just stop being whiney and install it. I'm sure that if I spend more than 5 mins trying to install it, it won't be much of a hassle. Trouble is "wanting" to do it. Heh.



			
				Praetor said:
			
		

> 4. Whats the ambient room temperature? PSUs become less and less efficient as the temperatures go up.


 
No more than 70° F. In the summer the temps climb above 100° F here. AC runs non-stop. The average temp is usually 65°-70° in the apartment.



			
				Praetor said:
			
		

> 5. As a test, turn the computer off for some time (an hour or so -- so that the PSU cools down), when you turn it on, go straight to the BIOS and note all the voltages (if your BIOS lets you). Then let your computer idle for about 20 minutes doing nothing and start your voltage logging ... once you have an idea how the voltages are during an 'idle' state, you may consider benchmarking your system (Prime95 works well although it generates a lot of heat, make sure your system can handle that too) and keep an eye on the voltages.


 
Again, still waiting for the cash to purchase a new power supply. But I will look into this too. And hopefully the power supply will last long enough to let it idle that long.



			
				Praetor said:
			
		

> 6. The onboard audio "simply dying" could be an indication that this may be a two prong problem: both the PSU and possibly the power regulation on the motherboard could be faulty (check your mobo visually for popped capacitors)


 
I was looking at it yesterday while reassembling it. I don't see any indication of probems other than I am somewhat lazy and need to dust more often (or invest in an air cleaner of some sort. But I took a dry lint-free cloth to every inch of it as gently as I could.


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## evilxp2800 (May 28, 2005)

They are Frustrating because my PSU Died on my other machine this week


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## DaveC (May 29, 2005)

evilxp2800 said:
			
		

> They are Frustrating because my PSU Died on my other machine this week


 
The funny thing though, is that I have a laptop for most of the time that i have been experiencing these probs and had no issue whatsoever. And in theory, notebook hardware is more expensive than desktop hardware. And it too is pretty much run off AC power 24/7. Did I just luck out? Hee hee.


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## jancz3rt (May 30, 2005)

*Power surge...*

I had a read through this as well. I have never come across this problem before. Could it be a sudden power surge of some sort? Is your notebook connected constantly to the plug? I doubt that. Anyway, I would first check out all the electric connections and try (if possible) to use the same plug as you use for the notebook? Just a though.

JAN


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## rufnkz (May 30, 2005)

I would suggest getting a UPS and connecting through it. (UPS is uninteruptible power supply.) These have a battery in them for when power drops below a certain voltage then the battery kicks in to drive the computer until the voltage is back up again. It sounds more like you are expierencing a small scale brownout where the voltage dips below 100 volts causing more current to be pulled. This occurs very frequently if a freezer or refrigerator is on the same line. A surge protector will not stop this from happening. If the voltage does drop the UPS will beep telling you it is being powered by the battery. Good luck!


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## Hairy_Lee (May 30, 2005)

judging by what he said earlier about psu's sparking i wouldn't have thought a drop in the voltage would be the problem but a surge.
im trying to think if equipment that would cause resonance in the circuit... got any equipment with large capacitors and stuff like motors on the same circuit?


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## rufnkz (May 30, 2005)

A drop in voltage increases amperage through the power supply frying components in the process. Any component could suffer and cause sparking in the PSU.


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## Hairy_Lee (May 30, 2005)

actually, a higher draw of current reduces voltage due to limitations of the supply... it often is caused by a failure of a component rather than a drop in the voltage.
by knowing this we can see that the a failure in a component, would cause an increase in the current being drawn, thus causing a drop in the voltage.
i love my job


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## rufnkz (May 31, 2005)

I will agree if it was a component failure from the start but try running the PSU at 80-90 volts and see what happens? A freezer or refridgerator on the same line constantly starting could reduce the voltage enough so that in a short time the PSU fails.


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## Hairy_Lee (May 31, 2005)

the only thing i could see something like a fridge doing is make it cut out due to not enough voltage. however, it might seem unlikely but i think there is a possibility of resonance which causes voltage amplification.
either that or there's something drawing too much current inside the pc that means the psu burnts out (which is more likely  ).


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## rufnkz (May 31, 2005)

Maybe his air conditioner is on same the circuit and is causing his problem. Either way I would assemble and take it over somebodys house and let them run it like he said. If he only was getting 1-7 days then keep it there two weeks and see.That many PSU's is not worth the hassle. 15 years of computer repair and I have never seen this before. Good luck and let us know what happens.


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## Scrat (May 31, 2005)

Could you post i high quality pic of the Mobo? i might then be able to point out some components to test... no promises


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## Praetor (May 31, 2005)

> I was looking into getting the OCZ PowerStream you recommended once the issue is resolved or at least figured out. What sort of devices would you recommend as far as preventing the power supply from exploding again? Some sort of power related hardware I mean. I have already invested about 100 bucks on a really good surge supressor. What else is available for issues like this?


Generally a UPS is a good idea although id avoid UPS that look like powerbars and get ones that look like boxes as they are a class above the powerbar type 



> Its definitely a possibility. The apartment I ive in isn't exactly the Ritz. It was built in the 60s. Which was the purpose of purchasing all the power hardware.


Grab a DMM and have a look (if you know what yer doing) as to what the voltages are. Also, is the PSU [potentially] overheating?



> No more than 70° F. In the summer the temps climb above 100° F here. AC runs non-stop. The average temp is usually 65°-70° in the apartment.


Computer isnt sharing same AC line as the AC is it?




> A drop in voltage increases amperage through the power supply frying components in the process.


Assuming power is conserved you'd be right however ATX specifications require overcurrent protection as well as stuff to deal with over and under voltage



> try running the PSU at 80-90 volts and see what happens?


In theory crap all since the PSU will have undervoltage/overcurrent protection kick in.


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## randruff (May 31, 2005)

DaveC, I really hope for the best for ya. Good luck with this!


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## DaveC (Jun 1, 2005)

jancz3rt said:
			
		

> I had a read through this as well. I have never come across this problem before. Could it be a sudden power surge of some sort? Is your notebook connected constantly to the plug? I doubt that. Anyway, I would first check out all the electric connections and try (if possible) to use the same plug as you use for the notebook? Just a though.
> 
> JAN


 
The notebook also runs 24/7 for the most part and just to be as technical as possible, they sit side by side on the desk and are plugged into the same surge protector.


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## DaveC (Jun 1, 2005)

rufnkz said:
			
		

> I would suggest getting a UPS and connecting through it. (UPS is uninteruptible power supply.) These have a battery in them for when power drops below a certain voltage then the battery kicks in to drive the computer until the voltage is back up again. It sounds more like you are expierencing a small scale brownout where the voltage dips below 100 volts causing more current to be pulled. This occurs very frequently if a freezer or refrigerator is on the same line. A surge protector will not stop this from happening. If the voltage does drop the UPS will beep telling you it is being powered by the battery. Good luck!


 
On the same line as how? I live in a small apartment and the only appliances that might have an effect are the AC, the fridge, and the dishwasher (all of which are on the opposite sides of the apartment).


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## DaveC (Jun 1, 2005)

rufnkz said:
			
		

> Maybe his air conditioner is on same the circuit and is causing his problem. Either way I would assemble and take it over somebodys house and let them run it like he said. If he only was getting 1-7 days then keep it there two weeks and see.That many PSU's is not worth the hassle. 15 years of computer repair and I have never seen this before. Good luck and let us know what happens.


 
How exactly do you test this? I'm willing to look into anything. But like I said.. I have been having this problem even during the spring when neither the AC nor the heater were on. Wouldn't that kind of rule it out?


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## Praetor (Jun 3, 2005)

> On the same line as how? I live in a small apartment and the only appliances that might have an effect are the AC, the fridge, and the dishwasher (all of which are on the opposite sides of the apartment).


Being on the opposite sides of the apartment then that possibility should be ruled out



> How exactly do you test this? I'm willing to look into anything. But like I said.. I have been having this problem even during the spring when neither the AC nor the heater were on. Wouldn't that kind of rule it out?


Yeah that would be kinda ruled out


Something you may want to try is to build yer system (say on the table so its easily accessible) and test the voltages (using say a DMM) every day maybe we can narrow down a rail or something thats failing you (if you cant do this, keep a log of the voltages say every hour)


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