My PC smells like burning

[Shadizar]

It has lasted for 3 weeks now. The PC smells badly burned, but the computer works perfectly. No crashes or boot problems, only the strong smell (which gives me headache). I've smelled my computer, and it smells bad all over the case. The worst stink comes from PSU, but also from top ventilation hole.

Temperatures are 45 CPU, 35 Chassis/AUX, 25 motherboard. System is 850Mhz TB and other stuff. PSU is Macase 300W, which is supposed to be high quality (at least it was the most expensive one at the store, about 80$). Voltages are 3.41, 5.05 and 12.40 and they are very steady and almost never vary.

My last computer was fried because of sucky PSU (KME 300W), and now the new comp smells just like the old one. Although every single component except CPU is totally new, straight out of the box. And CPU can't smell, or can it?

I have assembled the PC myself, this is maybe my fifth myself assembled PC, but could there be something about the assembling that's causing this smell?

[This message has been edited by Shadizar (edited 03-11-2001).]

[Paleo Pete]

Have you checked the voltage going in? Power surges or higher than normal voltage at the outlet would be the first thing I would suspect.

Have an electrician or the power company check it.

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[Shadizar]

I had before 3 years CeleronPC in the same power socket and it never had these problems. And voltages are extremely stable.

Someone at another forum said that this might be caused short circuit or burnout. Maybe the screws are contacting the motherboard and that's why mobo draws too much power from PSU, which is overloaded because of that. Which leads to overheating and frying PSU?

[Steve48]

Hello,
The noxious smell of fried carbon electronic parts is never good! If you can shut down your machine and remove the cover (if you have built your own, this should be E-Z) look for fried/melted cable runs. It is entierly possible that a circuit that is not used (yet) has gone bad, and you wont feel the effect till a later date. Also, (you should try this first) make sure that the PSU fan is indeed blowibg air! Ig it is not, it will only be a matter of time before your PSU and perhaps your entire system is nothing but a expensive paperwirght! Hope this helped!

[Steve48]

Me Again,

If you are using a AMD Thunderbird, MAKE SURE that you are using a AMD reccomended power supply! That is a MUST! Hope it helps!

[mjc]

Yes a short can lead to PSU problems including burnt circuits, I would suspect either faulty line voltage, like Pete said, or the PSU. Just as a test take a small amount of the heat sink compound and heat it, in a well ventilated area as many contain metallic salts, and see if the smell matches. Also see if the air coming from the PSU is inordinately hot.

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mjc
To ME or NOT to ME....

[Shadizar]

Air in the case is warm but not hot at all. I have 2 system blowers. I have tried PSU with hand, and it doesn't feel too warm either. But the PSU cooler is hardly workin! When I compare the airflow from PSU and from my Sunon system cooler (3000rpm), the Sunon is about 5 times more effective. There is hardly coming any air from PSU blower at all but the the cooler is spinning there. And when comparing to my other PC's PSU blower, the airflow is way better. PSU isn't in the AMD PSU list.

I checked my PC inside, and all the screws are in place and not contacting the motherboard.

I'm pretty sure that the source of smell is the PSU. Now I need to know what might cause stinking PSU, except broken one?
Could there be any reason for weak airflow of the PSU blower, overheating or odd behaviour of PSU in the assemble of PC?

[This message has been edited by Shadizar (edited 03-12-2001).]

[mjc]

Some thermal grease really smaell bad when they get too hot. Somtimes if you have too much on then extra will ooze all over and then(just hope its nonconductive) smoke and smell if it gets too hot.

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mjc
To ME or NOT to ME....

[Steve48]

Hello,

As mentioned before, you should really have a AMD reccomended powersuppy fot the Tbird CPU. But don't just take my word for it, ask around. It may be something AMD does with their CPU's to somehow control
the powersupply. But I would definitly get a different power supply!

Steve

[andreadebiase]

If you are sure that the smell is coming from PS I would immediately change it before getting a more serious problem!!!

[Randy_tx]

Replace the Power Supply ASAP !

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[Shadizar]

Originally posted by andreadebiase:
If you are sure that the smell is coming from PS I would immediately change it before getting a more serious problem!!!

I'm going to call to the store tomorrow and chance the PS. But I'm still curious if it's the PSU's fault. My last computer had exactly the same components, it smelled bad and the PSU fried whole comp. Now the new comp has same components but different PSU and PC still smells. It's hard to believe that it would faulty PSU again? And the new PSU is very expensive one, about $80.

What if I have just the same problem with third PSU? What then? Then it has to be something about the computer's components that stresses PSU or something.

[Randy_tx]

Might want to have your electrical outlet checked to see if you have a problem with the amount of current being delivered to the computer from your source of electricity.

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[Shadizar]

Now I have changed the PSU to working one, but the comp still smells exactly like last time. Any suggestions?

I tried kondensators (big batterylike things around CPU) and regulators after 2 hours of intense use. Regulators were all not even warm, but all the kondensators were hot, like the KT133 chip, which is almost hands burning hot.

[Randy_tx]

My advice......take it to someone who REALLY knows the Athalon and cooling of it.........real soon http://www.PCGuide.com/ubb/biggrin.gif

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[Shadizar]

Originally posted by Randy_tx:
My advice......take it to someone who REALLY knows the Athalon and cooling of it.........real soon http://www.PCGuide.com/ubb/biggrin.gif


You are underestimating me... http://www.PCGuide.com/ubb/frown.gif BTW. I don't have much experience with Athalon, is it a new model? http://www.PCGuide.com/ubb/biggrin.gif

I don't think it's a cooling issue. I have Alpha PEP66T with Sunon 25mm blower, the heatsink is correctly attached to CPU, I can even read the TB numbers from bottom of my heatsink http://www.PCGuide.com/ubb/biggrin.gif

I could take my PC to the store and they would somehow fix it and give me bill of couple hundred dollars, so I'd rather not.

Is there even a slightest chance that a CPU could cause this? Or Mobo?

[Randy_tx]

Did I understand you correctly.......you can read the information stamped on the cpu?? If you can, then you dont have a FAN COVERING THE CPU (which is crucial - a heatsink alone will not get the job done...even if a fan is nearby) ......you should NOT be able to read ANYthing on the cpu chip if your cooling setup is correct - A Heatsink with a 5000+rpm fan sitting right on the top, but connected to the heatsink.

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[This message has been edited by Randy_tx (edited 03-15-2001).]

[Reid]

Originally posted by Shadizar:
I tried kondensators (big batterylike things around CPU) and regulators after 2 hours of intense use. Regulators were all not even warm, but all the kondensators were hot, like the KT133 chip, which is almost hands burning hot.

If you are referring to the capacitors, they should not be getting hot. It has been a long time since I have experienced a burned out capacitor, but I believe it could account for the smell.

Some power supply fans are speed controlled and run slower (for reduced noise) when the temperature is low.

When you say you can read the TB number on the heatsink, do you mean that you can see the imprint in the heat sink compound when the heatsink is removed?


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reido@my-deja.com

Friends don't let friends install Windows ME

[Reid]

If the capacitors are heating up, it could be because of high-frequency and/or high-amplitude ripple from the power supply or the motherboard switching regulator.

"Switching power supplies like are found in almost all PC's these days use high frequency voltage converters to regulate voltage. The harmonics and noise produced by this rapid switching heats DC filter caps and causes them to loose moisture from their imperfect seals. This effect causes the capacitor to gradually open or drop in capacitive value."
http://www.repairfaq.org/REPAIR/F_captest.html

"..if an electrolytic is subjected to high temperatures, especially from heat generated internally by large ripple currents, the electrolyte will start to decompose and the dielectric may deteriorate, causing the Equivalent Series Resistance to increase far more rapidly. To make things worse, as the ESR increases, so does the amount of internal heating caused by ripple current. This can lead to an upward spiral in the capacitor's core temperature, and the electrolyte actually boiling."
http://www.flippers.com/esrkttxt.html


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reido@my-deja.com

Friends don't let friends install Windows ME

[Shadizar]

Originally posted by Randy_tx:
Did I understand you correctly.......you can read the information stamped on the cpu?? If you can, then you dont have a FAN COVERING THE CPU (which is crucial - a heatsink alone will not get the job done...even if a fan is nearby) ......you should NOT be able to read ANYthing on the cpu chip if your cooling setup is correct - A Heatsink with a 5000+rpm fan sitting right on the top, but connected to the heatsink.




LOL, I'm not THAT stupid. I mean I can read the info about CPU at the BOTTOM of the HEATSINK. It has been so hardly attached to the CPU, that it has actually printed CPU text on the copper of heatsink.

[Shadizar]

Thanks for the info, Reid.

I do have hot capacitors, but I'm not sure if they are abnormal hot. But if those aren't suppose to get warm at all, then the problem is propably there. To where does burning capacitors refer to? A broken motherboard, a bad CPU or lousy PSU?

[Reid]

I have worked on electronic equipment since 1964 and never found a capacitor that was running hot during operation, but did find evidence of overheating after some had completely failed. I would expect that an electrolytic capacitor would not usually feel warm to the touch, and especially should not feel burning hot. I have a Thunderbird 850 on an MSI K7T Pro-2, so I'll give a check to it for comparison, but when I was feeling around the heatsink during the initial operation, I didn't find anything hot.

I tend to think it may be caused by the power supply. The regulation and filtering may not be keeping up with the power demands.

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reido@my-deja.com

Friends don't let friends install Windows ME

[mjc]

Most capacitors should only be slightly warm, if they are approaching the temp of like the heatsink or hotter then they are too hot, BTW frying capacitors smell really bad. As to what caused it, it could be any of your suggestions but most probably a bad voltage regulator or the power supply, maybe even a short (look for excess solder, probably somewhere around the capacitors).

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mjc
I'm making my own links list:Computer Links (http://www.fortunecity.com/skyscraper/highrise/11/index.htm)

[Shadizar]

Originally posted by Reid:
I have worked on electronic equipment since 1964 and never found a capacitor that was running hot during operation, but did find evidence of overheating after some had completely failed. I would expect that an electrolytic capacitor would not usually feel warm to the touch, and especially should not feel burning hot. I have a Thunderbird 850 on an MSI K7T Pro-2, so I'll give a check to it for comparison, but when I was feeling around the heatsink during the initial operation, I didn't find anything hot.

I tend to think it may be caused by the power supply. The regulation and filtering may not be keeping up with the power demands.




I have too 850Mhz TB, but MSI K7T Pro2A. The capacitors are maybe not hot, but definitely they are warm. Maybe as warm as my heatsink which is about 35-40 degrees(CPU is 45 degrees max).

So what you are saying, is that the problem can only be PSU? So if not-smelling PSU is tested okay in one pc, it can't be smelly in some other pc(let's assume that both pc's require less than 300w, so it won't be overloading issue)? Then I just have to keep changing PSU's... Maybe Enermax or Antec this time.

[Randy_tx]

I'm not trying to evaluate your intelligence BTW, I'm trying to help you solve your problem ! Is there a fan interconnected to the heat sink or not? If yes, and running @ 5000 rpm or higher, you can probably eliminate the cpu/cooling area as the problem area.......if not, the cpu could easily be getting warm enough to burn any paint or residue on the heatsink and cause the odor without the cpu reaching critical temps and failing.

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"As hard as a rock & dumb as a brick"...Windows CEMeNT

[Shadizar]

Originally posted by Randy_tx:
Is there a fan interconnected to the heat sink or not?


Yes.

[Reid]

I can't say for certain that it is the power supply, but I wouldn't want to test it in another computer in case the power supply is bad. If it were mine, I could check ripple with an oscilloscope and set up the power supply externally with load resistors, which could help isolate whether it is a motherboard or power supply problem.

Does your case have in intake or exhaust fan in addition to the power supply fan? If not, some of the heat problem could be that the CPU fan is recirculating hot air, which could cause the capacitors and other components to heat up. The chipset unit with the heatsink is right in that area too, and your description sounds like that is hotter than it should be.

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reido@my-deja.com

Friends don't let friends install Windows ME

[This message has been edited by Reid (edited 03-16-2001).]

[Reid]

My mother board is a Pro2-A (I just left off the letter before). I opened after it had run for an hour and checked it while running. The capacitors are just barely warm, about the same temperature as the air blowing away from the heatsink. The chipset heatsink was warmer, but by no means hot. The CPU temp reads 41C and the chassis is 29C. I have an intake fan mounted on the front of the case.

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reido@my-deja.com

Friends don't let friends install Windows ME

[Shadizar]

I have 2 case coolers, but they are both on backpanel of the case. Down-one sucks air in and the upper one sucks it out. It's not ideal cooling, but the case doesn't get warm right now. My temps are by MSI utility: CPU 45 and chassis 35. Sandra shows that mobo is 25.

I felt the capacitors, they were warm, and after touching them, I clearly could feel some moisture in my fingertips. Like the capacitors would be little wet. I could hardly feel the moisture, but there is a little of moisture.

[mjc]

If that moisture felt a little sticky or very slippery then you probably have a leaking capacitor, also it may smell salty or oily.

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mjc
I'm making my own links list:Computer Links (http://www.fortunecity.com/skyscraper/highrise/11/index.htm)

[Shadizar]

The moisture wasn't sticky, slippery and it didn't smell at all. So I guess that's normal.

Someone at newsgroups said, that the mobo might be drawing bad or wrong voltage-amounts from the PSU. Is this even possible?

[Reid]

It is not normal for a capacitor to be wet. I still think a power supply problem is the most likely cause for them to have overheated in the first place, but I would be concerned that even if the power supply is replaced, the capacitors may fail later from the stress they have gone through.

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reido@my-deja.com

Friends don't let friends install Windows ME

[Shadizar]

I'm going to chance my second Macase PSU to Enermax 330W. I'm going to post here if it didn't help.

[Reid]

I hope that takes care of it. This is a very unusual problem and it is somewhat of a guess as to the cause.

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reido@my-deja.com

Friends don't let friends install Windows ME

[mjc]

Not sure if the dampness on the capacitors is the cause or a symptom,but like Reid said it isn't normal. If the power supply change doesn't help then the capacitors may be too far gone. Also clean everything well, trying to get any residue or thermal grease or anything else off the capacitors and MOBO. Just make sure that you are properly discharged (use a grounding wriststrap) and whatever you use (I'd use alcohol) dries completely before reinstalling the PSU and turning it on for the first time. Over here in the States you can get cans of spray cleaners to do that job at about any electronics store. Just look for a cleaner for circuit boards.

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mjc
I'm making my own links list:Computer Links (http://www.fortunecity.com/skyscraper/highrise/11/index.htm)