CPU Fan Failure Can Be Caused By Dust

Note: This may be something many other people already know, but because it's something I didn't know about when I got the "CPU Failure" message, following by the immediate shutting down of the machine, I assumed I needed a new CPU. I didn't, and that's why I thought I'd share the experience here.

My Compaq Presario, which has bordered on being completely silent in the few years since I've had it, has been making a little bit of noise over recent months. The increase in "clickety" sounds has been very gradual, so I haven't really noticed it (other than to know it had once been close to completely silent and no longer was). I suppose I was kind of thinking it was what happens when a PC is no longer brand new.

We've had lots of extremely humid weather in recent days. It's been so humid a couple of papers I have on my dining-room table actually felt soggy. The humidity and heat seemed to be at their peak when there was a power failure in the house. When I tried to get the computer going again that's when I first got the message, "CPU Fan Failure" (with an additional message along the lines that the PC would be shutting down immediately to prevent damage, and it should be serviced immediately).

Upon doing a little research, the first thing I learned was that I needed to figure out if the message was related to a fan at the back of the computer or a more challenging "cooling arrangement" that's apparently glued to a microchip and operates differently from a "basic, little, fan" at the back of the computer. Apparently, my machine has both types. The question was, "Which one failed?" I also learned that I needed to know if my machine even had a basic, little, fan (or whether it just uses the other kind).

Knowing the model number (SR5250NX) didn't help, because HP (which bought out Compaq a few years ago) technical information resources couldn't (apparently) tell me what this model has for cooling systems. It was a matter of needing to open the machine and look. I just thought it might be have nice if they knew that one model number has whatever it has for a cooling system, but they don't. My plan was, of course, to buy a fan (if I needed one) and either ask a friend/relative (who knows about these things better than I) to install it, or else bring the machine somewhere to have the work done. This wasn't my preference because if it was the basic fan, it appeared it, by itself, would cost between $30 and $40 (and some I'd run into were refurbished). Add what it would cost to "walk in the door" and then whatever else would be charged, and I wasn't thrilled at the surprise expense with which I'd potentially just been faced. (I have lots of those unexpected expenses as it is, as many people do.)

Maybe taking the side of the machine isn't much of a big deal for some people, but it is for me. I know nothing about the innards of a computer, and desktops are unwieldy for a lot of women (like me) to be moving out to a better location for taking the side off and seeing what's going on in there. Yes, I'm capable of recognizing a basic, little, fan at the back of the machine; but that's about it.

The machine first ran into problems Saturday. Sunday a software-designer/engineer friend offered to look at the machine to see which fan/cooling system had failed. When my friend took the side of the machine it was obvious there was lots of dust accumulation in there. He flicked the fan, and the machine almost immediately booted up. In case any is interested, it happens that my particular machine does have the basic fan at the back, as well as the other kind of cooling system. It became clear that the fan at the back of the machine blows out, while the other one blows downward. Based on what my friend said, that combination may contribute to the accumulation of dust on the back fan.

I'm guessing it may not help that my machine is at home, in a room not far from the kitchen; rather than in a "real" office. Between cooking in the kitchen, having window fans running (and bringing in stuff) about half the year, and the usual accumulation of dust; I don't think any of these things helped. It never occurred to me to get the machine checked for dust accumulation because for the first year, I was thinking it was a "new" machine. I guess the second year just flew, and soon it will be three years old. Live and learn (especially if your computer is not isolated in a "real" office, as opposed to being exposed to the things there are in the "regular" living area of a home.

It was quite a job for my friend to (kindly) clean it all out. He had brought a special cartridge used for cleaning in the inside of computers, so that helped. It wasn't nearly enough, though. In the end he needed to hand-brush the dust out of all the places it had settled. On the one hand, it probably wasn't absolutely essential that he clean it out so thoroughly. The fan had been blown and brushed off and was working. Still, who's going to close up the machine (after moving it to another room for working on it), knowing it's still full of dust.

So, my computer is now (mostly) dust-free, at least for now. There was no need to replace any fan of any kind. While the machine was open I wrote down the information we saw on it. It's IMPORTANT to emphasize that just because a model number may be the same as mine, it doesn't necessarily mean the fan will be the same. Still, I'm including the information I found in case it's of any use to you (should you find yourself with that "CPU Fan Failure" message on your own machine):

My model number is: SR5250NX. Here's what was inside the machine:

Fan Model: AUB 0812VH
12 Volt .41 Amp
Made by Delta Electronics/Made in China

The front of the fan has on it:

Asustek Computers Inc.
www.asus.com

Regardless of your computer's make or model number, you may find that having the following items on hand would be useful should you have the need to clean out dust:

Cartridges that clean blow the dust out by using compressed air. (You can learn more about them by looking online or asking where electronics products are sold.)

Brushes (such as unused paint brushes, such as the kind sold for children to use when painting with water or watercolors). (Very slim handle. Make sure the bristles don't look like they'll fall out easily, as with some cheaper brushes.)

Or, unused (but well made) make-up brushes with very slim handles.

Lint-free cloths or paper towels (for cleaning off the inside walls of the machine).

By the way: You can, if you must, bypass the error message by pressing F2 (according the HP information I found. Apparently, others bypass the message with F1, although not necessarily with the same kind of PC as mine). Obviously, this isn't recommended because your machine could be damaged if it runs without being adequately cooled. There are times when the error message may appear any number of reasons, and not necessarily related to the fan's not working. This is yet another reason to take the side of the machine and at least see if a) there's a back fan at all (some machines have more complex/advanced cooling systems that don't involve a back fan at all; although in the case of mine, there are, as I mentioned, both).

In any case, if it happens there's a back fan and it isn't working, that will be obvious and "more mysterious" causes for the message can be eliminated. Mine was working again, with the machine booting up (and staying on) with the flick of a finger (even before all that cleaning). Since finding part numbers isn't all that easy (apparently), if your machine has this kind of fan and you need to replace it, it's good to know what kind you have before ordering a new one.

In the case of my machine, HP does offer step-by-step instructions for replacing the fan. (I, personally, would still be uncomfortable attempting to do that - but maybe that's just me and the fact that I'm intimidated by just thinking about replacing anything in my PC.)