I'm trying to save my aging computer from imminent doom
, since buying a new system is not in the cards for me at the moment. My problems are with cooling fans. I have a 550 MhZ AMD Athlon system with a Microstar MS-6167 motherboard (I bought it ten or eleven years ago right when the Athlon processor was first introduced) and a Matrox G400-max display card (way back then, this was top-o-the-line). A few weeks ago something didn't sound quite right to me
so I took the cover off the computer and saw that the cooling fan on the Matrox video card wasn't spinning at all. I gently prodded it with my finger and it started to work, but since the end was obviously near for it I started shopping for a fan. The original fan is 40mm x 40mm and 5V DC@0.13 amps, which apparently is unusual, but a somewhat nearby hardcore electronics store had one (only one type, and the last one in stock as well) with a similar wattage rating (5V@0.19 amps). The guy at the store told me this was a rare type of fan and he wouldn't be restocking it or getting similar ones in ever, so I guess it was lucky they even had one. I then went to install the new fan and noticed that the original one has three power wires while the new one I purchased has only two power wires coming out of it. Perhaps foolishly
I figured it wasn't important, and started to install the new fan. I had to stop, though, because the new fan is a little thicker than the old one (10mm vs 6mm) and I didn't have the right size screws to secure it. I put the old fan back on and put the computer back together until I could get the proper screws.
Since I was concerned about the video card getting too hot, I've been running the computer without the cover so I can keep an eye on it. I didn't have time to go to the hardware store for the screws, so I've been going on this way for a few weeks, and the Matrox cooling fan has been working fine for now (obviously however it can't be trusted and must be replaced). Two days ago I was very deeply disturbed to see that when I turned on the computer the CPU cooling fan did not start to spin and was making a loud noise
. I prodded it with my finger and it started spinning, but this situation seemed to be something that a professional would refer to as Really, Really Bad
. Since I've been running the computer with the case open anyway to keep an eye on the video card fan, I've been closely watching the CPU fan as well so that if it stops spinning I can shut down the computer immediately. The fan has been working but it's very loud now (I did look and there are no obstructions) so I can tell the bearings are about to fail any moment.
Since the CPU fan is a pretty common (or so I thought) 12V 50mm type, I was very surprised that when I went to several local computer shops none of them had an appropriate fan in stock. One young clerk at one of the stores told me this was a "highly specialized type of item" and I had to restrain myself
from laughing in his face as these type of fans were used in millions of computers for many years. Unfortunately the hardcore electronics shop where I got the other fan is in another town, and although I'm pretty sure they would have a replacement CPU fan I can't get over there anytime soon. I dug into my closet where I have a couple of old (even older than what I'm currently using) computers I keep for nostalgia value and the first one I checked had a 12V CPU fan of the proper size so I pulled it out. Looking at it however, I see that it also is a two power wire fan, while the current CPU fan in my computer is a three-wire type that plugs into the motherboard.
I did a little research online and found out that in three-wire cooling fans, the extra third wire is used to detect and monitor the RPM of the fan. In newer computers I guess the motherboard will control the RPM to maintain a constant temperature at the CPU, but I'm guessing that in my old computer it's probably only used to simply detect if the fan is in fact turning at all or has stopped/failed. However, I did not see any sort of error messages when either the video card fan or the CPU fan had their stoppage incidents
, so I'm not sure if I even have any monitoring capability or if it is working on my older system.
Now that I'm aware of the purpose of all the wires on the three-wire fans, but have only two-wire fans with which to replace them, I'm not sure what to do especially since I feel urgently compelled to fix both fan problems immediately--sitting here listening to how sick they sound is highly unnerving--and I don't want to waste more time trying to find the correct (and presumably very rare) fans for my old computer unless it is absolutely-positively necessary. Does anyone have a suggestion about how I should proceed? My online research wasn't very informative about whether it would be safe to go ahead and replace the three-wire fans with two-wire versions since a few Google hits said to never attempt this but gave no specific reason why, while a few others said don't worry you'll just get some trivial error messages that can be ignored. I'm not sure which of these random search-engine results to trust, which is why I'm asking for the opinions of those I trust here at
Posette Forever since in addition to being fine artists there seem to be many generally technically-minded folks here as well.
In looking at the other really old computers in my closet I saw that another one had a 12V 50mm fan that hooks up to the hard drive power supply plugs using a pass-through plug, so I guess another option I have on my table is to use this old fan for the CPU. However the computer that fan was in doesn't work and I no longer remember why it failed, so this second fan should be considered of questionable value although I guess I could cut and splice the connectors onto the first fan I want to use as a replacement for the CPU fan. This then would allow me to power the CPU fan directly off the general power supply instead of through the motherboard (as the Athlon system is currently configured to do). However, this is a bit of extra work and would cram even more jumbling wires into my already cramped computer case, plus would not solve the question of what to do about the video card fan and the three-wire/two-wire issue on that.
Does anyone have any suggestions or have any experience with the operation of older PC cooling fans? I know I'm a cheapskate, and while there's no doubt I've gotten my money's worth out of this old computer I want to keep on stretching life out of it until the bitter end.
Thanks
Endosphere