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Is Your Computer a Fire Hazard Waiting to Happen?
whoppers asks: "I'm sure we've all had our share of computer fans die, but what happens if your box is running while you're at work and several fans go out? My in-laws spare TigerPC AMD K62-400's power supply fan just went out about two hours ago, and the thing was blazing hot. A little poke to the blade, and it started up again, but shouldn't these things be made to stop if the fan stops for any reason? I'm starting to wonder if I should start leaving my box off when I'm away for a few hours. Since it's usually wide open, I don't see too much harm, but these cheap boxes that never get opened and cleaned have to be a hazard right? I can't afford a halon system in my office just yet. The only link I found related to this is here and should a few more people read this, here's the cached version. Does anyone have any thoughts or stories related to this?" The fact that this article appears on July 4th, when most Americans will be lighting fireworks is purely coincidental. That doesn't change the fact that the submittor raises a very good point.
A general rule of computers is: the older they get, the more dusty they are and dust bunnies and their denser cousins are highly flammable. Unless you can keep such machines clean, it' is probably safer to leave them off.
The only link I found related to this is here and should a few more people read this, here's the cached version.
A link to the cached version? Come on, this is Slashdot. What's the worst that could happen?
Yeah, old comps do get dusty inside. However, even if the fan quits, it's still not a problem. That bit of dust is flammible, but the metal aint. There's a fireproof box around those bunnies. ANd once it smolders some, it'll burn out most of the O2 (since the fans dont pump air cause of dust). There goes your "fire hazard"
The only thing is it's a boring news day.
the new ASUS motherboads have COP : CPU Overheating Protection, which switches off the machine when temp goes baloony.
And they're damd fine MoBo's too...
When will I end this grieving ? When will my future begin ?
You have nothing to worry about. They test for things like the fan stopping.
Eventually, when the heat gets too high, the power supply will either shut off or destroy itself.
The UL/CSA logo (if its genuine -- many cheap power supplies don't put on genuine labels) "guarantees" the power supply won't be dangerous to you. A flaming power supply would be, obviously.
Hope that allys your fears!
If you could be told what you can see or read, then it follows that you could be told what to say or think - BoC
Maybe insurance companies should offer discounts to those of us with common sense enough to buy and configure motherboards that have a "Power Off on High Temperature" option in the BIOS. Haven't these motherboards been available for a long time?!
IF you dont let the dust build up by useing a vacuum onece a month or so, that drasticaly reduces the fire hazard. Of course, that doesnt mean your CPU fan wont fail, causing your CPU to burn right through your motherboard if you dont have overheat protection. ;-)
At work they made a policy that ALL computers will be completely shut down at night after a monitor caught fire one night and burned out an office. Normal hardware shouldn't catch fire even when old/crusty but there's NO guarantees when the hardware is defective to start with.
Many modern motherboards power automatically power down when the CPU gets too hot, but that is just the CPU .. I think the greatest danger in modern computers is the power supply.
At work we recently had a problem where a paperclip fell inside the grilles in the power supply and shorted something out, causing power surges which trashed the rest of the computer, which wasn't nice.
But what was worse was the smell of the thing, it was really nasty. When capacitors burn due to having too much current put across them, they release all sorts of nasty toxins and also fibres which can stick to your clothes and make them smell for ages. Or even worse, stick to you skin and eyes and burn or blind you.
It's not just fires that are a hazard. Computers, and indeed most electronic devices, consist of many environmentally unhealthy and hazardous chemicals.
If I had a webcam, I'd post a link to a photo.
:)
I'm running Win 98 on a Cyrix M2 233MHz overclocked to 300MHz (came when I bought it).
I paid 2500 rupees for the processor, [ 1 US$ = 48 Rupees - do your math], and thus don't really care much about it.
Anyway, it's 40 degrees here in Delhi, I don't have an AC, and my CPU Fan's bust for *over a week*. And it's happened several times before.
What do I do? I take off the Hood, Put my ceiling fan to "Maximum" and keep on Photoshopping.
I'm a comp Sc student, and I know what I'm doing is insane.
but, Hey, As long as it's running, Who cares?
Fans are designed to move air - like any fluid motion, air will move along the path of least resistance. In the case of a case fan, where the case is left open, you're pulling air from a very small area right in front of the fan before exhausting it out the back. The heat generating components (CPUs, hard drives, video chips, etc) tend to be far enough away from these fans that you'll see almost 0 airflow over them.
I used to work for a major hard drive manufacturer, and would get complains from users who said our drives were running too hot. Quite often, they said "I even leave the case off, and it's still too hot!". Many times, just putting the case on solved their heat problems. By creating essentially a duct for the air to flow through, the fan was able to pull air from the front of the case, across the heat generating components, and then exhaust it out the back.
In the case of components with their own fans (CPUs, video chips), this is still important - while you've exhausted the hot air from around the component, without a properly functioning (read: case on) case cooling system, that hot air is never removed from the general area around the component, and just gets sucked back in on the intake side of the fan.
Just my $.02.
-- "Other than that, how was the play Mrs. Lincoln?"
Even if the computer never over heats dust and oils and other icks can still kill a computer. I once was trying to fix a women's computer that had stopped. I opened up the case and the entire motherboard was covered in oil and fur. Turned out she let her cat sleep on it all the time and never cleaned it. All that direct exposure to animal bits just killed it. She had to buy a new computer.
I now religiously check the dust levels of my computers.
Feminism is the radical notion that women are people.
Just like anything else give it a simple cleaning. I'm sure every now and then you take a simple duster to some of your stuff. It's very easy to buy a can of compressed air and then use the compressed air to clean out the dust bunnies. Once every 6 months or so and you should be fine. There are also cases that prevent this very thing, as it's too hot for me to be on my computer right now I'll just explain the case I have. I have a Lian Li that I bought from thinkgeek it has a filter system in the front. A filter is placed above two high speed fans (who's speed can be set) that catch dust and that is removeable and cleaneable. Dust still gets in the case but it's alot less and my cleaning time is really only annual if I want. Even if you don't have fans in your case electricity can attract those dust balls at the foot of your box very easily so it's not just a matter of fans or moving parts it's really just a matter of cleanliness.. Smoking, dustballs, dirt, etc can all cause problems.. but a regular dusting helps.
They are screaming:"Computer nerd started fire and takes down entire block of houses!"
I've always questioned this myself since I always leave my computers running and the athlons keep getting so hot. My parents used to hate it when I left home and left the computers running, but now I've got my own place it's much bigger an issue than before. I do like the fact that most of my Macs hardly use their fans, or don't have fans at all. This keeps me a little less paranoid when I'm not at home. It's also a bit of a problem that in my place (small town in The Netherland) does not have broadband access and I have no possibility at all to check up on my systems when I'm away. Anybody got a few hints fow me?
--- In a world without fences, who needs Gates.
I have an IBM Thinkpad A20P. Great machine, but one day I was typing on it and felt unbelievable amounts of heat coming off the top of the keyboard. Just as I was remarking to my coworkers about it, the machine halted to a black (no, not a blue screen; I can't remember if I was booted into Linux or Win2K at the time). Anyways, I power-cycled, and the BIOS halted again with a "Fan Failure" error. Aha. So I whistled it over to the service depot (under warranty) and they found that a long human hair had been sucked into the air intake and wrapped itself around the fan, halting it.
Thank you IBM, for building systems that watch for this kind of thing. One step friendlier could have been a user warning (through a BIOS video overlay) that said "HIGH TEMPERATURE ALARM - POWERING DOWN IN 10 SECONDS" or something, to allow a user (if present) to save some of their work. Anyways, at least it didn't keep running and cook my CPU, hard disk, and everything else they pack into such a small space on these notebooks.
...and in fact the author of the article states as much. Apparently the real concern is that the plastics/dust in the case will set off a smoke alarm, thus diverting firefighting resources to something that is apparently not "life threatning" ... unless someone is keeping gasoline in their case, I don't think is something we need to lose sleep over.
I used to work in an engineering shop. The place was dirty and dusty as hell which caused computer equipment in the engineering office (read "big shack in main building") to become dirty and dusty as hell. One day something was giving off a burning plastic smell...
Phil: What's that burning plastic smell?
Fred: It's your monitor, it's on fire.
Phil's monitor had caught fire. Of course the monitor was destroyed but people were around to put it out and keep anything really bad from happening.
Two months later...
Phil: What's that burning plastic smell?
Fred: Your monitor is on fire again.
Phil's replacement monitor had caught fire. That was the last computer monitor fire they had that I know of. It didn't stop Phil from leaving his monitor on every night when he went home from work.
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I too had my share of dead fans in the past 2 months. 3 fans (out of 4) died on my 3 years old computer: PSU fan and both CPU fans (dual setup). Only the front fan survived (as of yet).
The thing is, even without sensors, I still have caught the failing PSU fan. When it stopped, the PSU got hotter (as what happened to the poster in-laws), but after reaching a certain temp it just shutdown itself. And I couldn't get the computer to restart immediately after (before knowing what was causing the trouble), since the temperature was still too hot for the PSU to allow power to flow. I'm talking about a cheap 250W DTK ATX power supply from 3 years ago. After letting it rest a little, I retried, and while booting it shutdown again. The third time I tried to access the something on the back, and then noticed that no airflow was going out of the PSU.
For the 2 CPU fans, the motherboard RPM sensors saved both my CPUs (and the fact that I was watching them at the right time).
On a modern computer (where fans can and will die given enough time), a plethora of programs can be run in the background to check the RPM of fans and the different temperatures in the system. Just make it alert the user (or shutdown if no action is taken in x time) in case of one parameter going outside it's normal range. Check overclocking sites for info on that, since they usually tend to have more problems with that then plain desktop users.
Also, the MTBF for cheap DC fans is usually around 20000 hours. That means a bit less than 2 hours and a half. Either replace them beofre, check them cautiously before that mark, or get some higher quality fans (which will tend to be quieter, too).
Another solution is to go with watercooling (but then, if there's a spill AND you're fluid is conductive, the fire hazard is still present). You've only got a pump and a fan (for the heat exchanger) which can die, rather than 3+ fans in a typical computer case (yea, I know, SPOF, but they're more robust).
My friend has an old IBM PS/1 that's a 486 with a Pentium Overdrive chip that he uses as a print server. While he's been away, I've had to fix the machine. It was scorching hot to the touch and I thought the power supply was going bad.
After considerable effort, I removed the power supply with the intention of replacing it with another AT one that I found. Unfortunately, the power supply had extra proprietary connectors and the replacement one didn't, so I was left to figure how to fix the original one.
I took a closer look and I saw nine (9) years (!) worth of dust clogging the power supply fan, thus blocking its motion. Ignoring printed warnings as "Caution! Shock Hazard" and "Warning: No User Serviceable parts inside", I carefully opened the power supply and removed the fan. Fortunately, the fan had a plaster connector for easy plugging/unplugging (as opposed to being soldered directly to the board).
So I removed the fan with easy and scraped (yes, SCRAPED!) the crap off of it and wiped it down. Then I applied WD-40 to the bearings to get the fan blade with more ease. I had to help the WD-40 spread by using a screwdriver to turn the fan both directions. Finally, after 20 minutes of effort, the fan blade was turning reasonably well with I'd tap it, so I put it back in, reconnected it, and reassembled the power supply.
Once the computer was put back together, I turned it on and felt for heat. Not alot. For the first time in a while, there was ventilation coming from the back of the power supply and the system was running much cooler than before.
So, let this be a lesson to you. Make sure you regularly (yearly?) clean your fans off, removing the dust before it cakes on. Make sure that you do this to any older PCs you have or are about to obtain.
Otherwise, your system will run dangerously hot and only bad things can come of that.
Twice I have had a (rather large) UPS explode. When a UPS goes, it goes spectacularly. Really explodes. Smoke, fire, huge BANG. Talk about dangerous. We actually had one UPS disintegrate into pieces... luckly nobody was close at the time.
Monitors can also be pretty spectacular. Where I live we get 150 to 200 inches of rain a year... needless to say, it's frequently damp. I've had monitors, when turned on, explode (luckly never the screen though, only the power supply). We tend to leave all our equipment on, and baking, to avoid this - but still we go through a monitor a year (we are starting to replace them with LCD, we'll see how those stand up to the elements).
But the worst were definatly the UPS - especially since they are near your feet - they can be very dangerous indeed.
My computer has three fans, i installed some extra since the one fan on the power supply died and my computer started to become unstable. I started to get Compile errors, i destroyed half of my Memory or so memtest86 told me. machine temperature got over 50 degrees in the box, the cpu was at 70 degrees celsius.
:)
I bought two extra fans and a new power supply the machine is running like a charm ever since
You wont see three fans die at once, better save then sorry.
How come nobody has made a case with an air filter on it so you only have to brush off the filter every month instead of taking a can of air to the box?
I don't see a great fire hazard here. Sure, dust bunnies are flammable, but it would take an extremely hot processor to ignite them, and even then it would be more of a quick flame than a real fire. I just can't see the electronics or the case catching fire.
Bottom line: You might lose your PC, but it will be a very quick and self-contained fire. And considering how extremely unlikely it is to happen, I'd say don't worry.
It just ocurred to me that water cooling might double as a great fire-extinguisher... since a fire in the case would probably sever the hoses. Then again, if you're water cooling, your processor will never get that hot... never mind.
Seeing as how you have an AMD I'm thinking your motherboard doesn't have buil-in protection against overheating. I'm not too familiar with hardware but isn't the chip the only thing that gets really hot? If so when the fan goes off either your chip should slow by its self or the motherboard should slow it down for you, in either case your chip shouldn't overheat.
As to the dust being a fire hazard and assuming it is still a risk at normal operating temperatures (which your box should not exceed by much for the previously stated reason), the only real solution would be to clean it out.
I stole this Sig
Use an air compressor on your computer if you want a fine mist of water sprayed over all your expensive electronics. Air compressors have drain plugs for a reason!
Your much better off just buying cans of "compressed air" (it's actually not air per se).
Actually most OS have can be rigged to do a proper shutdown if the fans stop provided the motherboard supports it.
Thats one thing that i like about the Intel Pentium III and IV processors. If the CPU fan were to die on the PIII chip, the processor would simply halt all processing if the chip temp. got to high. In the Pentium IV processors, if the fan dies, the CPU will actually down clock itself until it reaches a safe temp. to keep running at. Although I dont know what you could do if the PS fan were to die; i wonder if you could rig something up similar to the fail safe in the P3 chip that would simply shut the power off if the temp. got to high. In any case, the one thing that i did that helps keep all those dust bunnies out of my case was to install washable filters on all the fan spots. That makes it a hell of a lot easier to clean, plus i dont need to clean out the inside of the case anywhere near as much anymore.
Instead of chasing windmills, let's have a poll on this.
Spontaneous computer combustion:
( ) Seen it
( ) Heard of it
( ) Heard of someone who heard of someone who...
( ) Nope
My point is, is this really an issue to worry about?
Unable to read configuration file '/bigassraid/htdig//conf/14229.conf'
Geocrawler error message.
What if the power supply fan dies, and the power supply itself overheats and dies? Thats a bitchen place to have a fire, as you have a nice high voltage (120ac) high current enviroment to feed it. Thats why i own a portable air compressor (one of those 150$ jobs). Its great for showing up at the client's site and blowing out all their machines.
Lawyers, MBA's, RIAA? A jedi fears not these things!
My motherboard (kt7) shuts down the computer if it gets too hot. I assumed this was a common feature on *most* new motherboards.
Cruise TT
The illustrated guide to breaking your computer shows you the correct and incorrect way to light your computer on fire.
Just make sure the air compressor isn't spitting some liquid out with the air (many spit some water vapor as well).
SIG: HUP
Which a great deal of them aren't. With most of the computers I've owned, if I took the side panel of the case off, the CPU ran a full 8-10 degrees C cooler than with the case fully closed. This is primarily because the poor case cooling meant that the air inside the case was 10 C or so hotter than room temperature, so removing the side panel let the CPU fan suck in cooler outside air to blow on the heatsink (since the CPU fan is at 90 degrees to the motherboard, it's good at sucking air directly from outside if the side panel of the case is off).
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
is that there is very little risk.
1. If the fan stops, airflow basically stops. Air contains oxygen, which is required for oxidation (!). There isn't very much air in a typical case.
2. Fire requires fuel. If you have two ounces of dust and three ounces of flame resistant insulation in your case you don't have much of a fuel source. You aren't going to reach temperatures to cause a metal fire. Fiberglass doesn't burn.
3. The third element of fire is heat. Paper burns at 451 degrees F. The burning point of your draperies is probably higher. Your CPU will fail, and at least temporarily stop generating heat, well below that temperature. I expect a power supply would as well.
So, the bottom line is that you could probably contrive a set of circumstances that would produce a "PC fire," but the odds of one happening spontaneously are virtually nil. Perhaps on a similar scale with the odds of your alarm clock/radio shorting out and catching your nightstand on fire. Undeniably possible, but undeniably remote.
-Peter
Dust is potentially flammable, and it's also conductive, which could makr a circuit where there isn't suuposed to be one, but your computer will definately catch on fire if you are infected with Monkeypoo.
VIRUS WARNING:
Attention: Computer Labs Inc., makers of Virucide antivirus software have identified a highly dangerous new Trojan worm, MONKEYPOO. It will usually appear in an e-mail with the subject, "Congratulations.You have won!" it will then prompt you to click a link to collect your cash prize. It can also freely spread across networks.
Monkeypoo will read your address book, and mail a copy of itself to every address it finds, and it will look like you sent it. It will then invoke the secret self-destruct command held over from the original IBM PC's 8086 command set. This short line of code will cause the processor, ram, hard drive and any floppy drives to spin out of control and overheat until key components melt together, and will most likely cause a fire.
James Winklee, a former IBM programmer had this to say. "We developed the self-destruct code so government agencies such as the FBI and CIA could quickly and completely destroy compromised computer systems before an enemy could get their hands on classified information. When we saw how violently a PC executing the command burst into flames, we decides not to publish it's existence. It has been kept a secret successfully until now. If you get infected with the Monkeypoo Trojan worm, you may notice your computer going completely haywire. Physically unplug it from power as fast as you can, and send it in for repair. Only a professional can remove this one."
While Computer Labs Inc and other antivirus software makers are working on a solution, they haven't got one a home user could successfully run yet. "This is the worst kind of malicious code I have ever seen." said Marcus Polan of Computer labs Inc. Use extreme caution.
It is important that as many computer users as possible receive this warning, so send it out to as many people as you can. The entire Internet and every PC connected to it is at risk.
How ya like dat?
Air compressors are so much fun for cleaning computers. Try aiming the output directly at a fan. Spins faster than it was ever designed :). Yeah, I know it's not smart... but it's FUN!
Doing that will likely destroy the bearings, so you'll be replacing those fans soon, too. Please, if you're going to use compressed air to clean out the computer, stop the fans from moving so that you don't destroy them.
Yeah, except you have to reach a temperature at which the plastic will create a self-sustaining fire for this to happen. What temperature do you think butane burns at? Ever tried to burn plastic with a lighter? Ever tried to burn paper with a naked CPU?
/their/ burning temperature. I think that the clear answer is "no."
The whole question hinged on wether a CPU or PS will reach a high enough temperature to raise nearby combustibles to
-Peter
It's cheaper, and much less likely to kill you.
Sorry, but the concentration of CO2 that is necessary to put out a fire is also insufficient to support human life. The neat thing about Halon is that it doesn't do immediate harm to humans at the concentration that puts out a fire, as long as you leave the area quickly. I knew somebody who was in a room when Halon was accidentally released, and it had no effect on him ...
Toronto-area transit rider? Rate your ride.
What are you getting at? It's quite easy to burn plastic with a butane lighter... (trust me, I do it all the time)
The PPC runs much cooler than its x86 cousins. Mac cases also tend to be built with convection cooling in mind with vents on back and sides unlike most solid metal cases sold for use as x86 machines. The inside of my G3 didn't start running at all warm until I installed a VooDoo5/5500 card (that thing pumps out some heat).
I'm not looking to start a war here, but this is simply just one aspect of the Mac that most people seem to like: the cases. Many articles and revires pine over the Mac's enclosures, wishing some generic case vendor would attempt something like that for the modders on the x86 side.
Article X: The powers not delegated... by the Constitution...are reserved...to the people
All computer power supplies have temperature sensors.
You may be an MCSE, but you're no electronics guru. I've got four different manufacturer's AT and ATX power supplies here, open, and none have thermal sensors.
Now there's a really expensive one in my server which does, but it uses it to regulate how fast to spin the fan. I see fuses, MOVs, NTCs and the usual array of electronic devices in these power supplies. That's it.
Mac OS X will terminate on an overheat signal. On the new XServe, the machine can be configured to send an alarm or shut down upon fan failure.
But I guess you get what you pay for, since Macs can be significantly more expensive.
How easy would it be to integrate that sort of thing into all the flavors of Windows or into Linux?
I've seen Watchdog cards used for this purpose. When the temp rises above X deg. it performs an orderly shutdown. I believe there are IBM desktops and servers that have this feature built in.
Perhaps more applicable in this case is that these boards also offer inputs for fan speed sensing when used with an appropriate fan (generally the ones with 3 wires and a small tach sensor built in). Unfortunately, I have yet to see a power supply that comes with such a fan and provides the sensor feedback to go back to the motherboard. (I'm not saying they don't make them, just in my limited experience I haven't seen any.) If you could find the right size fan with the speed sensor you should be able to install it in the power supply and route it to the MB though. If there was enough demand voiced I expect the sensor would start showing up, but manufacturers would have to know that some people we basing case purchases on this feature.
This doesn't help older systems like this Tiger system much, but the issue has been addressed. There also have been available for quite some time temperature sensors that you installed in the case and they would sound an alarm when a critical temperature was reached. Several years ago I had a programmer build some watchdog timers for some critical systems with PIC chips and we decided to add a Dallas temperature sensor. By tapping on the reset button a few times you could get it to beep the internal case temperature back to you.(Obviously, you didn't reset the computer - the watchdog took over the MB reset input so it could reboot the system if it detected a failure. A long press of the reset could still reset the system through the PIC chip.)
This is reasonably timely for me, just yesterday I started getting alarms that my CPU fan was erratically slowing down. So far CPU temp looks good, but I'm going to have to replace the fan (if I can find an available fan of the right size with a speed sensor) or the whole heat sink assembly. I do have another 12 volt fan with the right hole pattern, but it lacks the speed sensor and is much thicker. Maybe I could find some really long metal screws and stack both fans above the heat sink, count on the new one to cool the CPU, but the old one to help and to continue to monitor the RPM and airflow. Any thoughts?
I'm an American. I love this country and the freedoms that we used to have.
I put a DIMM in backwards once when I wasn't paying attention. The computer didn't POST when I tried turning it back on, and it must have run for about 20 seconds before I gave up and would try to reseat the memory. So I turned the box back off and reached in to reseat the memory. It was at that point when I learned an important lesson about how damn hot those things get when seated incorrectly, ow.. There was no permanent damage to the components though and no melting :P
I am curious what is the point of Titanium bearings?
Bearings generally stop because of grease failure or contamination. There is rarely spalling of the raceways or rolling elements.
PS I work for one of those 3 lettered companies.
I used to leave my machines on 24/7, but found that this accounted for the majority of my electric bill, not to mention sometimes needing AC, and having the disks wear out earlier. Just a thought.
JET Program: see Japan, meet intere
Burn or melt? I'm sure you can get it to go around the edges a bit, but does it burn anywhere near as easily as paper? Based on your vast plastic burning experience do you think that a CPU without a fan can reach that temperature?
Can we agree that paper burns more easily than plastic? Can you burn paper with your CPU?
-Peter
My PS fan on my older P200 tower died when I was away and eventually the surge protectors breaker tripped. Scary thought. I have three machines at the house that currently run 24/7. After that and a few more instances of fan failure, I now actually check the fans with my hand at least once daily. My main Samba server has had two fan failures in the last two years. One I noticed because I could not telnet in anymore. The second I felt the heat when I was reaching around to check the fan. The server has only been down 3 times in two years and two of them were because of the damn PS fan. A word of advice.. If the fan starts to make noise or you notice it running slower, replace it ASAP!
Bad boys rape our young girls but Violet gives willingly.
If you didn't notice until the smell came out, how do you know it stopped an *hour* before?
The power supply will burn itself out before it catches anything on fire. "Dust bunnies" are highly combustible but they typically don't burn long enough, only a couple of seconds, to catch anything else on fire. The real danger with the computer is probably the power strip. Make sure you spring for a good quality, UL listed power strip. The cheap ones make poor connection with the plug and use smaller-gauge wire internally and for the cord, thus increasing the risk of fire under heavy load.
maru
Tom's Hardware Guide showed how the CPUs had reached 300 and 370 degrees C in the infamous thermal tests once the cooling was shot. The ignition temperature for paper is typically in the 175-200 degree range.
My dad's PC had an unfortunate accident that could have easily sent the house up in flames if it weren't for the people there at the time.
His system was an Athlon 1.4 with SCSI, a Radeon, lots of RAM and other suitably expensive stuff (at the time), excepting the NIC. The NIC was a generic cheapo and for some unknown reason it decided to spontaneously burst into flames.
If it wasn't for the various case fans blowing the smoke out into the house, we wouldn't have known. Luckily we got to it before the rest of the PC (and potentially the house) followed suit. The motherboard and the NIC were the only things that needed replacing, but we took the hint and replaced all our cheapo NICs with hopefully less flammable 3Coms.
It was a lucky escape and it certainly made us think twice about leaving our boxen running 24/7, especially unattended. Flammability isn't something I usually take into consideration when buying components. Suffice to say, no more Happy Value components for me.
Oh, and if anyone's wondering; The smell of a burning PC is very nasty. Incredibly, the OS was still alive before I cut the power. I'm also persuaded that if we had bought a cheapo case with poor ventilation, the component death toll would have been much higher. Heh.. maybe those watercooling monkeys can set up an internal sprinkler system or something. Hahah.
My life is one big siesta in which I'm dreaming I wished my life was one big siesta.
So far I've been unlucky enough to have two systems go ablaze, and they've been fairly dust-free for most of their operating lives -- I tend to dust (and vacuum) them every month or so.
The first was a dual-processor Pentium II board that caught fire around an inductor about a year ago. Thankfully, the case was closed and the little blaze starved itself of oxygen, and was fairly controlled. It was a small fire around the inductor, so it was going nowhere, although several nearby chips actually popped off the board. See the pictures, if you dare:
Burnout 1
Burnout 2
Burnout 3
Yeah, it was pretty nasty. My room was filled with smoke for a day or so, even with the window open and a fan blowing exhaust out my window.
The second was the ATX connector on a Pentium III motherboard actually heating up to the point of melting both the connector on the board and the connector on the power supply, so all that was left was a mess of molten plastic and some bare pins. Needless to say, both the power supply and motherboard were thrown in my local dumpster.
Anyone have similar experience? Or am I just an unlucky bastard?
A month ago I received a clients PC for repair. She claimed that it just up-and-stopped running one day.
Being kind of doubtful, and suspecting user stupidity, I cracked it open, and found nothing wrong...supposedly. I then popped the cover off the power supply, to find some nice char.
A bit more testing found that the motherboard would take _no_ power. I had picked up the machine from her house, so I knew the power was fine, and she was also using an excellent surge unit.
The PC was a bottom of the line Gateway, with a no-name power supply. Not suprising.
I see a few steps I can take to improve my shelf o'computers. I'm going to move my printers to another table, remove excess wires and monitors, and other non esential materials. The insides of my boxes are clean. Smoke detectors and insurance can't hold a candle to prevention.
Friends don't help friends install M$ junk.
a friend of mine had his computer lock up and noticed that his hard drive was in flames, apparently due to faulty wiring in the pcb.
http://www.ews.uiuc.edu/~atwell/toast/
it didn't hurt anything other than the power supply (apparently overloaded from the short), but i'm told it was a harrowing experience.
( ) Coyboy Neal poured gasoline on it
Toms Hardware did a test where the heat sink was removed from 4 kinds of processors while they where in heavy use. The P4 stepped down the speed until it managed a safe temp. The P3 halted and the two types of Athlons incinerated. (It hit 698 degrees almost instantly once the heat sink was removed.) Maybe the P4 is worth the extra cash. http://www.tomshardware.com/cpu/01q3/010917/index. html
Also, depending on what failed with the fan, you might well be better off replacing it if at all possible. Just because it spins again doesn't mean it is going to continue spinning for another few years, it might very well fail within the month.
Actually the fact that the power supply was still running might be testament to the quality, I've seen too many newer power supplies fail way too soon, some taking most of the rest of the computer with them.
Bleh!
If it was a significant problem, there would be more stories of it happening. "My fan died and burned my house down" is the kind of story that would spread pretty well on the net.
It seems I forgot to make my point in the last post. :-)
My point was that there are lots of other fire hazards in your average home, most of them more dangerous than the computer. I've never seen a computer catch fire, but I've seen pics of appliances as diverse as refrigerators and washing mashines (!) be the cause of domestic fires.
So, my point was along "I'd take precautions for the general case and don't worry so much".
There are quite a few different kinds of paper. While 451 deg is a great meme, in reality it's lower for household paper (such as newspapers). It's higher for book-quality color prints.
:-)
Besides, most of this is hypothetical. I wouldn't worry about the CPU igniting newspapers
Be really careful with those buggers, namely the box between the wall and the computer. It puts out a ton of heat. I once had one get stuck in the couch overnight and the plastic had *melted*. That was a close one. Be ye warned.
Josh Woodward
Computers are not designed or approved to be run open. It's a stupid thing to do if you are afraid of fire--they get less air circulation, they run hotter, and if they catch fire, the fire can more easily spread. Running your computer open also violates FCC rules because it will cause lots of interference, affecting radio operators, police and fire communications, baby monitors, and medical equipment.
Computers are designed with metal cases for good reasons: they allow the fans to work, they conduct heat, they keep RF inside, and they offer some protection against fire. Don't run your computer open--it's just stupid.
dust bunnies in the case you probably have under control, but don't forget the psu. that has shock warning stickers on it because it _can_ kill you, so if you're not qualified, take it to someone who is for a quick cleaning once in a while. bring them sushi.
the amount of crud in an older psu can be just incredible. a few AT's i've opened had charred dust.
a few people have mentioned UL safety tests. generally this is correct, but keep in mind some outfits ship cheapened components hoping they won't get caught in an inspection.
some have also mentioned that the pc isn't likely to burn down your house because of some dust smoldering inside the steel box. likely this it true, even if the capacitors explode. make sure this is true for you by not burying your box under papers and pushing it against a curtain behind your desk. just have a look -- if it was on fire right now would it ignite anything alongside? no? then in a worst case senario you'll be woken by your fire alarm and can leave the house okay. some dust on fire isn't going to asphyxiate you.
don't forget the monitor. one of mine tried to catch fire but i caught it and yanked the cord. just got some smoke. probably the UL safety would have saved it anyway, but if those capacitors had burst first... now i shut down when i leave the area.
now guestimate how many offices leave monitors running screensavers all night since 1985 versus how many fires you've heard of. computer fire is a very low risk. take some basic precautions and relax. traffic is what you should be afraid of, and your bathtub, and maybe tetris.
Under both Windows (Motherboard Moniter) and linux (lm_sensors) software exisits that can moniter the built in thermal and fan sensors that most modern motherboards have, and can be configured to shut down your computer when it overheats or a fan fails.
Sure it will cause some extra wear. You might even be able to measure it with the most sensitive equipment available. But is there really any reason to believe that doing this will cause the fan to fail any sooner. Not counting some statistical likelyhood to fail three seconds sooner.
Blog,Twitter
I'd presume that the switching regulator IC would have some sort of thermal protection in it, even if it just failed when it got too hot.
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
http://mbm.livewiredev.com/ has the programs. they're for windows...motherboard monitor keeps you informed of the temp (and you can set it to email you if your equipment hits a certain temp or something) and you can also set it to trigger ShutDownNow (linked from that site above)...which will do the shutdown routine for Windows.
FreeBSD for the impatient.
This seems like a ridiculous and unnecessary design to me. There are already perforations in the metal front of the case where the fan should be mounted -- why not put some slits in the plastic front of the case as well, so air can be sucked in from there directly, instead of through the opening at the bottom?
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
Are you going to cite any specific examples of UL being unreliable, or are you going to continue talking out of your ass?
"Remember, there never were pineapple-almond cookies here."
Sure it will cause some extra wear. You might even be able to measure it with the most sensitive equipment available. But is there really any reason to believe that doing this will cause the fan to fail any sooner. Not counting some statistical likelyhood to fail three seconds sooner.
Not true. Those fans are designed to spin at ~4500rpm. Just like a car engine, rev too high and you can spin the bearings. And despite sounding like what they're designed to do, spinning bearings and/or scaring the raceways they run in is a bad thing. It causes premature failure that is measured by years, not seconds.
You know, just because you know the ins and outs of VB and Perl doesn't make you a mechanical expert as well.
I'd presume that the switching regulator IC would have some sort of thermal protection in it, even if it just failed when it got too hot.
Most linear regulators do this (the entire 78xx/79xx family is great for this exact reason) but chips like the venerable LM723 (I think that's the right number) and practically the entire line of Unitrode parts has no built in thermal protection whatsoever. You can build that in to the feedback loop or the power sequencing part of the supply, of course, but that costs money. :-)
Silicon won't necessarily save you, because the tempco could be negative (bipolar transistors, for example, have a negative tempco) which means that as they get hotter, they conduct better. Conducting better means they will draw more current, and the resulting positive feedback loop quickly leads to thermal runaway. MOSFETs don't have this problem but the actual switches aren't the only thing to go wrong in switchers. IIRC the opto used in the feedback loop often employs a bipolar phototransistor which leads to supply brownouts when it gets hot. (i.e. the Current Transfer Ratio goes from 1:300 to 1:500 so when the LED is at half intensity the supply thinks that it's putting out a higher voltage than it really is and overcompensates.)There are very good reasons why electronics designers are often heard mumbling and grumbling along the lines of "there's no faster fuse than silicon," and "if you use a $0.05 fuse and a $35.00 transistor, the transistor will blow apart to protect the fuse."
I've found that just laying my case down lowers the temp (only by 1-2degs to be honest). I figure this is due to the fact the CPU will be facing upward and so the heatsink is working more efficiently.
I've also found that adding a fan to the top of the case to pull the hot air out (on upright cases) makes a BIG difference, especially on smaller cases designed for the MATX boards. I had an athlon in a small case that was running at 60-65degs and very unstable until I cut a hole and put a fan in the top - it dropped the temp to 50-55degs and hasn't crashed since.
I think the biggest single difference I've made was adding a Coolermaster "Heatpipe" heatsink to an Athlon - that thing knocked 15 degrees off the CPU temp immediately! I had to remove it again though, as the noise was unbearable... It makes a nice-looking paperweight though!
Also little things like tidying up a rats-nest of wiring and putting dummy plates over unused expansion slot cut-outs in the case helps.
Code, Hardware, stuff like that.
I assume its part of the ATI drivers, but Win2k displays an error message that the fan has stopped spinning whenever it happens on the FireGL card in one of my machines at work (I need to poke in there and clear the dust I think)....I assume it would be possible to write a script that shuts down the machine if such an event occurs. There are plenty of utilities that will monitor core temps and fan speeds from within your OS (as opposed to BIOS level)....and since most good power supplies run the fan as a variable speed powered off the motherboard....shouldn't be to hard.
I'm out of my mind right now, but feel free to leave a message.....
People cover the vents on their iMacs? It must take them a while to do it then, because the back of the macine is sloped. That's one of the conveniences Apple ran into with their design: it would take conscious effort (and possibly tape) to block the vents.
Lack of eloquence does not denote lack of intelligence, though they often coincide.
A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
Caught fire - BORING. When I was young I replaced a PSU with 4 step-down high-power resistors (no mains isolation) with a bridge rectifier and capacitor. It burned bright red, started to pop, then exploded into a fireball spurting burning (ceramic?) fireballs everywhere. Needless to say MOBO+HD+VID were blown and the power rails on the MOBO sizzled spattering the inside of the case with solder rain.
A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
Moral of this story - mechanical engineer thinks about the bearings, electrical engineer thinks about the motor and stator, software engineer thinks about RAID-5.
A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
VaxWars has an insteresting story about that very thing. Rather humerous read. After you read that, I reccomend you check out the VaxBar for another good laugh.
--MonMotha
After a few minutes, I went to inspect the damage, fearing my linux box had died! It turns out that one of those mini-fan power hookups (the ones with two prongs sticking out) had touch another piece of metal inside the case and shorted. The resulting powersurge heated up the wires, melting the protective rubber coating. Fortunately, that's all the damage that occured. I clipped the wires out, turned on the computer and all was good.
The moral of the story is, don't leave those fan power hookup cables floating free inside your case. I can just imagine what would've happened if I had already gone to work and my wife and daughter were still asleep when that happened.
Looking for a computer support specialist for your small business? Check out
The platters rang like a bell when hit, even when sitting on the carpet. Get a set of platters from different drives together and you could do the Anvil Chorus.
Paul.
You are lost in a twisty maze of little standards, all different.
That's not too surprising really, considering that pretty much all power-supplies these days are switched-mode instead of the old transformer type.
Transformers use coils where current from one induces a current in the other. Although these fail sometimes, when coils short together, generally this will just cause a lower induced current in the output coil, and a lower resistance on the input coil which will hopefully causing the fuse to the PSU to blow.
Switched-mode power supplies instead chop up the input AC signal, rectify it and smooth it. However, this also means that if a component in the PSU fails, your component is effectively directly connected to the mains and it's quite likely that your devices willget the full 110V / 220V put across them. This is generally a bad thing.
Ever wondered why power-supplies from the last 10 years or so are so much lighter than older ones?
Hmmm. I have carpet in mine, lining all edges of the case to reduce vibrations and consequently noise. But then most of that noise is due to the 6 fans I have inside my case... I think I will investigate water cooling when I have more money.
stuck fan overcurrent
Um you do realize that every fan in your computer is impedance protected, don't you? If you stop the fan with your finger the current does not rise significantly at all, and the very design of most of these fans does nothing to self-cool.
Moral of this story - mechanical engineer thinks about the bearings, electrical engineer thinks about the motor and stator, software engineer thinks about RAID-5.
And systems engineers (like me) think about everything. :-) Admittedly I don't design computers (embedded industrial control systems is where I hang my hat) but I stand by my statements. Overspeeding motors of any kind often causes bearing damage which leads to premature failure of the motor. Contamination of the bearing lubricant also causes premature failure of the motor. There is a happy middle ground and it involves not overspeeding the motor when you hit it with the air gun. :-)
In industrial motors e.g. 5kW corporate AirCon units a big fan is attached to the rotor to cool the motor itself. It's assumed that the fan won't fail (same as ships assume propellers won't fail causing overspeed if it does) and that the motor will run with a minimum RPM (otherwise the rotor fan will lose CFM whilst increasing heat is generated by the current through the windings to handle the torque). High resistance windings in 5kW motors to withstand stalling strikes me as very inefficient. I scaled it down to small fans, hmmmmmmm, can still cause a burnt commutator.
A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
Ahhh, that's good design, many motors are fan cooled (the fan being driven by the rotor). In computer fans I assumed a proportion of the airflow from was used to cool the motor.
I thought so too. Unlike "normal" motors, the stator in these little muffin fans is the center and the rotor is the outside. There's a "hoop" of magnetic material which makes up the rotor and then you have your coils and control electronics on a small PCB at the center (stator). I can't see much airflow getting up into that area. These aren't much like the AC industrial motors I play with where the stator is packed against the outside frame and the shaft fan blows air across/through the motor.
In industrial motors e.g. 5kW corporate AirCon units a big fan is attached to the rotor to cool the motor itself. It's assumed that the fan won't fail (same as ships assume propellers won't fail causing overspeed if it does) and that the motor will run with a minimum RPM (otherwise the rotor fan will lose CFM whilst increasing heat is generated by the current through the windings to handle the torque). High resistance windings in 5kW motors to withstand stalling strikes me as very inefficient. I scaled it down to small fans, hmmmmmmm, can still cause a burnt commutator.
Exactly. I used to design AC soft starters so the rotor spinning at anything other than 1450rpm for significant time was rare. (We did some 7 and 14% jogging but we time-limited the operation.) Now that we're into variable frequency drives the norm is to have a much smaller blower motor driving the fan instead of having the fan hang of the rear shaft of the drive motor.
A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
Functionally, it works as a lubricant fairly nicely. Also as a cleaner. It also kills ants, and, with a lighter held in front of it, is a fun party tool. It may not be the best at any of these, but it functions pretty well as a general purpose tool - I keep a small can in my toolbox, and usually have a large one around. For parties.
I agree with everything you've said except for *one* thing.
Don't use WD-40 as a lubricant. Use it as a penetrating oil, to free stuck and seized moving parts. But once they're unstuck, clean them thoroughly with carb cleaner or something similar, and then use a proper oil or grease to lubricate them.
Speaking from experience, WD-40 turns sticky with time. Small machines (ie. computer fans) will seize.
If you *have* to lubricate a disassembled computer fan, use ONE drop of the lightest machine oil you can find - the smallest SAE viscosity number.
However, dust in the air passing through the fan will magically be attracted to the bearings and trapped in the oil, where it will eventually seize the fan again.
Good computer fans have graphite-impregnated sleeve bearings. When the bearing ceases to be self-lubricating, the bearing is worn out and it's time to replace the fan.
Cheap computer fans (and those sold to people who don't know any better) use tiny little ball bearing assemblies. With outside bearing diameters of less than 1/8" in some cases, the balls are absolutely tiny, especially relative to any dust which might become trapped in them. The "ball bearing" fans are especially prone to failure, and should also be avoided, unless you're buying expensive ball-bearing fans for use in your clean room.
Replace the fans. If you have to take them apart to clean/lube them, they're finished, and will fail again soon.
www.papstplc.com
and, manufacturer of the legendary Muffin Fan used everywhere from Cray computers to the Space Shuttle,
www.comairrotron.com
I don't believe in repairing cooling fans, and I don't believe in the cheap crap which washes ashore from Taiwan and infiltrates our computer cases.
Buy good fans. They'll outlast your computers, and you'll never need to do more than vacuum them.
Fire and Meat. Yummy.
No. Old-school power supplies worked by transforming 120VAC at 60hz into the desired output voltage at 60hz, then rectifying and filtering it. Thing is, an inductor must be very large and heavy to work at 60hz (you need an iron core roughly the size of a small fist). New style power supplies first rectify and filter the 120VAC into 120VDC. It is then inverted into AC at a much higher frequency (usually 20khz to 500khz). Then it is transformed to the output voltage and rectified/filtered into DC. The higher frequencies are what allows for much smaller/lighter transformers and capacitors. Your mains potential is still separated from your load by the transformer, though.
Oh dear - you're obviously reluctant to try that again but perhaps you're not sure why, so let's do the math. Your average computer needs about 100 watts to run. Let's simplify things and assume for a second that they only need 12VDC as well. That's 8.5 amps. In order for a series voltage divider to work, your resistors must eat 90% of the voltage (120/(120-12)) - 108 volts. 108 volts at 8.5 amps is 918 watts, roughly the same as a large element on a kitchen stove. Divide this by 4 and you get 229 watts per resistor. I don't believe you can buy those kinds of resistors at Radio Shack.
Also, if you fried the motherboard, then your resistors were probably of too low a value. You need 12.7 ohms total, so for a bridge rectifier where only two of the diodes would be conducting at any given time and the resistors would effectively be in series, you'd want 6.4 ohm resistors. Mouser sells a 6.8 ohm 300 watt resistor that would work. Make sure to bolt it to a heatsink of the proper size.
So now you know what you need to fix before you try it again, and this time, please, get the solder rain on videotape.
My calculations were correct but wrong (smoothing capacitor but no voltage regulator). Many components e.g. fans, hard disk motors have slow-start so they consume less current at start. V=IR so less current through the resistor means lower voltage differential across the resistor which means overvoltage on the motherboard. My voltmeter told me I put +45V on the 5V power rail before I heard popping and sizzling. Hmmmmmmm.
My Uncle made the same mistake as me except he's a mechanical engineer. He was fixing a mower and it had a 13 amp fuse, it was live and he dropped a screwdriver which unluckily landed on the live and neutral wires simultaneously. The fuse blew in about 0.5 seconds, after the 13-amp certified wires had boiled away. ER said if he wasn't wearing his safety glasses he'd be blind. They had to pick the solder balls out of his face one by one, it took 3 hours. The Doc said the last time he saw an injury like that was when a dog tried to attack a porcupine..
No way, I'm a "professional engineer" now so I know it was stupid. Mains isolation is cool, you don't know who's going to be tinkering inside the case.A caveman dreams of being us, the incalculable power and riches. We dream of being Q, then what?
You know what sucks? How come there isn't a thread specifically for challenging moderation?
I had a chance to meta-moderate this post, and I said the 'troll' (or was it flamebait?) moderation was unfair. And I will continue to mark these types of things unfair as long as Slashdot doesn't have a forum for griping about unfair moderations.
Mod-bombing does happen. I got hit by it in April. Here's some proof:
http://www.nanogator.com/slashdot.jpg
I wouldn't go as far as to liken Slashdot to Nazis like the parent poster did, but I do think it's awful that there isn't a forum to discuss this. The worst part is that we can't bring it up in the thread that it happens in. I challenged a posting I made once and it got modded down as 'off-topic'.
So wtf?
I have a feeling this post is going to get modded down because I'm not talking about my computer as a fire hazard. Oh well, at least I've expressed myself.
I really wish that moderators would be careful about who they mod down. We've all seen too many instances of people getting modded down because their opinion's different from your own. I'll never forget getting modded down because I said Flash was a cool product. All the hatred against Flash anims cost me karma even though I was specifically talking about it from the development point of view. *eyeroll*
"Derp de derp."
I've dealt with quite a few systems that have had dead fans for unknown periods of time. Worst case is the system locks or a drive fails from heat. I've never seen a fire.
My big gripe is cheap cooling fans. Now, I don't really complain about the nasty sleeve bearing fans used on cheap power supplies, because...they're cheap. You expect it.
Now, take my Quantum DLT changer. One of the cheapo sleeve bearing cooling fans dies. Tape drive overheats. Tape that was loaded is shot. The two tapes nearest the drive in the magazine threw lots of errors. And for a while, I wasn't even sure if the drive had survived, but it appears to have worked. So I order a $25 fan from Mouser, snip out the piece of shit that was in there, and put in the new fan. Because somebody at Quantum decided to save a couple of dollars on a multi-thousand dollar piece of equipment, I lost three DLT tapes and hours of time, not to mention a night's backups.
What I'd really like to see is more use of paddles with microswitches. A lot of telecom equipment uses these little sheet metal paddles in the airstream of each fan. If the air stops, the paddle moves to resting position, and switches a microswitch. From there, it's alarm, cut power to the system, or whatever is appropriate.