My new desktop build's CPU didn't stop working, but the system was saying "fan error" at boot, so I looked in the case. First I noticed that yes, it had stopped; then I noticed that below it, a black rounded rubber band was now hanging loosely on a corner of the heatsink. Well, that pretty much tells me what must have happened: the rubber band must be a belt (what else? I didn't have any rubber bands in the case) and I need to buy a new fan. I know it's obviously broken, but am I right? A belt popped loose? No wonder I heard the fan clank before it started.

I immediately shut down and went back to this laptop. Oh, well, that was an old fan left over from my last desktop computer (but used for only a year or two). I'm off to get a new one.

I've never seen any fans inside a computer powered by a belt...

Some fans have bearings inside which might of failed and caused the clanking.

If it wasn't a belt, it wasn't. But that leaves me with a mystery: how a round-edged black rubber band, not particularly large, was hanging just on the upper left corner of the heat sink under the fan. Where it would have come from. My utility rubber bands look like one might expect: flat-edged and beige. I haven't bothered yet to take the fan off the CPU and examine it closely for some sort of damage. I just turned off the computer and put it aside.

It only just occurred to me to remember than automotive fans use belts (I don't drive!), so I wonder if anyone's going to tell me I must not know the difference between a computer and an automobile. I mean you haven't and don't necessarily think so; but LQ is large...

There are some fairly interesting looking cooling fan/heatsinks out there. Let us know when you take a better look.

Have you checked the manual for the motherboard? It should be available at the manufacturer's website.

Well, no, I haven't done that just, because it was the fan that went out. The motherboard didn't appear to have anything wrong, because the computer was still running with the fan off (though it wouldn't go past the boot screen) for the minute or so I took to realize it wasn't running and shut down.

There could be a coincidence here, I guess: the fan fails at exactly the same time I discover a small black rubber band hanging just below it, which came from I know not where.

Modern cpu fans have 3+ wires to so the system can measure and adjust their speed. The BIOS will check the speed at boot up and if not running will shutdown the computer.

In the past I have used rubber bands to tie up long switch wires that came with the case.

Okay, I just pulled the fan off the CPU (ugh, I have to watch the still-fairly wet paste) and examined it. I know where the rubber band is probably from: the space between the blades and the label-displaying flat-nosed front of the fan.

I'd better identify my fan model and find a photo. https://i.ebayimg.com/images/g/RigAA...Gjd/s-l300.jpg Thermaltake TR2 R1 TT. A cursory look showed me that this rubber band would fit perfectly in this narrow, round space that is now empty. The band most likely fell out of there. I don't suppose it's a belt as such, but I'm sure it came from the fan. I admit I don't know how it would come out, because it's not broken.

I just have to ask since you mentioned this is a new build. What CPU uses a Fan/HS like that anymore? Isn't it loud? Perhaps more importantly what sort of temperatures did/does your CPU average?

I thought the "rubber band" may have actually been a gasket but seeing that photo, I doubt it.

No, I don't mind explaining. It is technically a new build, but most parts are not new. This was an experiment in seeing to what extent I could get away with using old, obsolete (which usually meant used) components. I'll skip describing them individually because you asked about the fan specifically. The fan is/was left over from my last desktop computer build; I bought it eight or nine years ago and used it for around a year before the motherboard failed, and it's been in my box of parts ever since. So that particular re-use didn't work; I cheerfully bought a new one.

(Why did I try to build a computer of mainly used parts? Because I've been successfully using used computers for the last eight years--old ThinkPad laptops. I decided I wanted to go back to a desktop computer, and my years of using decade-old ThinkPads taught me that I don't need anything close to top-of-the-line.)

The band may been binding up some cables and have come loose?

That is if it is a band and not some kind of gasket? I've not personally seen any heatsink and fan which use a gasket (to dampen vibration) but there are so many products out there that I suppose it's possible.

Thank you, newbiesforever for expanding. I happen to agree at least in large. My laptop is an ancient IBM Thinkpad T61p I bought used for ~90 bux (around $1750+, new). Recently I bought a 250GB Samsung SATA SSD for 40bux and it is very fast and pleasant AND it has no MCE which for me is a plus. So we share a basic conclusion, at least for some use cases.

I do have one problem with that T61p that directly relates to your problem and my response. My T61p cooled down a bit by switching from a 7200 rpm mechanical drive to an SSD but it still runs uncomfortably hot. It's uncomfortable both physically and emotionally because, coming from the electronics field, I am painfully aware it does not pay to cut costs on cooling.

Thankfully what used to be a tiny niche of PC enthusiasts has become a huge mainstream market, that of high performance gear that includes cooling solutions. Even a cheapo HS/Fan combo costing just 30 bux these days will run cooler, quieter, and longer than ones that cost close to 100 bux just 10 years ago.

There are areas of hardware that lose very little by going old or going cheap but power supplies and cooling isn't such an area.

PS - Sometimes we are forced out of older gear by lack of support. I have an old box that uses an LGA 775 Core 2 Extreme CPU that is still just amazingly fast and potent, but it's UEFI implementation hasn't been updated by Intel for over 6 years and it will not boot an NVME drive in a PCIe slot without painstaking and difficult (not to mention risky) modification of the UEFI image. Very frustrating.

Yes, we even use similar laptop models and even the same exact one at times. I started with a T61. I'd just rather not go older than a T400 (what I use now) because T61 won't take more than 4 GB RAM (if I recall). It's basically because of money that I wanted to stop using these laptops. Or, the annoyance of buying new laptops too often. I buy them used at eBay; and I have to replace them relatively often, because they break. I've never had one last more than a year and a half. Replacements are cheap: I can generally find a new one that looks in good shape for a hundred bucks; but something always eventually fails--the cooling system, the screen, the CPU. I was tired of buying a new one sometimes as often as every six months. My last desktop computer build lasted about five years and thus a desktop computer started looking better.

Contrary to what a recent post title would suggest, I'm no Luddite, but I am quite frugal. When my happy use of ancient laptops taught me that I don't need brand new technology, I was eager to run with that conclusion. I once met someone who said "You should use the latest and greatest technology, [expletive]!" and now I think he was quite foolish.

I bought the T61P exactly because of it's age. It was the last series built by IBM (matters only a little) and the last model in which the BIOS does not have MCE (I often laugh at how close that is to MCP from Tron in function as well as name). The MCE has serious potential for spying on us but we can't even know if it is because it's proprietary. Nevertheless even while sleeping it has access to hard drives and networking. It's very rare that I actually travel with a laptop but since it is trivial to do so, I chose to err on the side of safety and privacy and 4GB RAM is plenty with Linux-only and what I want to do with any laptop. BTW an SSD, even on so old a laptop is a performance boost that no amount of ram can match and a helluva lot cheaper.

As opposed to laptop usage, I'm on my Desktop PCs for many hours every day. I completely agree with you that Desktop PCs are wiser not only for longevity but upgrade-ability. It should be obvious that I'm pretty frugal, too, but I've been building PCs so long that I have had to learn a few hard lessons. It is possible to go overboard maintaining old gear. Because technology goes up at almost the same rate that prices come down, there does come a point where it is no longer cost efficient to continue with old gear. Another thread here about Flat Panel Displays highlights one such issue. BIOS/UEFI is another.

On the flip side it is difficult to accept that I own a couple dozen really decent PCI cards that are useless on my newest and largely useless on my previous PC (1 PCI slot). However everything is much faster and more efficient... frugal isn't easy

I agree with enorbet. Vintage cars or antiques may have their own lovable features. But vintage electronics are plain stupid. I worked with electronics since the late 1970s, and when you buy new, you can count on up to 5 good years from something. The sympathy or affection for older electronics leads to frustrating unreliability that robs time and energy, and underproduces.

Parts are obsolete within 3 years anyhow. Standards keep changing. What started as an 8 bit data bus through which everything traveled on an 8 bit computer running at a cpu speed of 1 Mhz has become 128 bit data buses on 64bit cpus doing Ghz on multiple cores augmented by very fast SIO lines driving your PCI Express cards.

Now if you're a man of leisure and enjoy playing with old stuff, enjoy yourself. Having had that kicked out of me by commercial reality, I wouldn't boast about it.