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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 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...
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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).
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.
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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?
Link.
Yes, specced clock and voltage, and then heat sink shot (removed) to see what happened. The overheating ones were AMD procs; Pentiums did not (I say again, DID NOT) overheat anywhere near these temperatures.
I don't remember the ignition temp for your average plastic, but I do remember (from office fire safety training) that paper tended to have the lowest ignition temp of everyday materials, closely followed by wood. My associations to burning plastic are more along the lines of "toxic as hell so get out", I don't remember a specific temperature.
Ignition temperature for paper is 451 deg Farenheit, hence the title of the book. For the rest of the world, that's 233 deg Celsius. Still lower than what a bare CPU can reach.
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.
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.
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Having dealt with several failed fans in the history of being a service technician, I must say I have never seen a fire related to a fan failure. Most of the time people bring them in because of a smell and before anything shorts out. I replaced the fan and the warranty is void sticker with our shops and send it home. (now supplies are cheap so we just replace the supply except for the hard to get proprotiory junk)
Most smoke issues seen have been:
Ruptured filter capacitors. They have a steam rupture due to the electrolytic. (the end blowes out some times ejecting the roll of tin foil) Boiling water is not hot enough for any flames and the spacer is still wet and won't catch fire.
Shorted power transistors. These may smoke the case of the transistor or take out some flameproof resistors before taking out the main fuse, but again no flames. Shorted disk ceramic or tantilium capitors. These are not made of flamable materials. Last is Metal Oxide Varistors (surge protectors). These tend to smoke the covering, but the part itself is made of non-flamable materials.
In monitors, shorted high voltage supply transformer and the degausing thermistor The transformers really stink with a burning plastic and tar oder, but they are built with self extinguishing materials. The thermistors smoke the plastic covering, but the part itself is not flamable. Again, never had seen a flame continue burning after the fuse or regulated power supply removed the power.
In summary, unless you get enough combustible lint near a severely overheated part, the risk of fire is very low.
The only fire issues I have ever heard about were caused by some defective battery packs for a laptop. There was a massive recall for the batteries. I certanly wouldn't a flaming laptop in my lap. I may want children someday.
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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.
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and, manufacturer of the legendary Muffin Fan used everywhere from Cray computers to the Space Shuttle,
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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.
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