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Alienware M15X - CPU fan not working properly

6K views 21 replies 6 participants last post by  Saturable 
#1 ·
http://tvtropes.org/pmwiki/pmwiki.php/Main/ExactlyWhatItSaysOnTheTin

Just kidding.

But seriously, today I got a second-hand Alienware M15X, and immediately it has a major problem. Only one fan in the machine, the GPU fan, actually works. The CPU fan, on the other hand, just barely turns on. Right now, I can put my hand over its vent and feel a very small amount of air coming out of it, but practically nothing compared to the GPU fan's vent.

At first, I thought it was a problem having to do with the vent. I opened up the fan assembly, and found that the vent was almost completely blocked by random wads of hair (this thing did come off of Ebay, after all). I cleaned all that crap out, put it back together, and the overheating still persisted. It took me a minute to realize that the fan wasn't even running, as I can only hear the GPU fan running.

As you can probably guess, the CPU fan not operating results in severe slowdowns. Just Cause 2, for example, broke down to 10 FPS on absolute minimal settings because of this. It's also pretty obvious when you hold the laptop itself - one side of it is completely cool, while the other is running 80C+.

Right now, my plan is to get a cooling pad as a temporary fix, and get a replacement fan if necessary. Before I bother getting a replacement fan, though, I want to know: is there any way to actually fix this? From what I found on Google, this isn't a problem exclusive to me, but seems to happen to a lot of M15X's. I've tried to see if SpeedFan could help at all, but to no avail. Little help?
 
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#3 ·
Replacing it isn't the thing I have a problem with. The thing I have a problem with is actually doing the replacing, because I'm always scared I'm going to break something. (Yeah, I know, squeamish over computers. XD)
 
#4 ·
Well Imma be frank then. I wouldn't recommend doing it yourself. Don't take this as a sign of me "knocking" on your skills or anything. The reason is that laptops are MUCH more complicated to work on than desktops and if you're not a "handy" person in that regard might be beat to jave it replaces by a local shop. I would assume they would charge somewhere around 30$ to do it, but it would be peace of mind it was done right :)
 
#5 ·
A fan replacement is probably one of the easiest replacements for a laptop. That is, unless there are components in the way of the fan.
They usually connect straight to the motherboard via a single cable. Sometimes these cables are really secure in there, so I recommend using a small Flathead to push up on the plastic portion on one side and then the other (rinse and repeat) until you ease it out. While you can pull on the cable directly, it's not recommended because you could end up separating the cable from the plastic connector. But since the fan is broken, it won't really matter if you destroy the cable.

But if you feel this is out of your range of competence, don't push yourself. It'll cost a whole lot more to have a computer repair shop do it for you, but you get the benefit of them knowing what they're doing (unless they don't, so pick a reputable shop).
 
#6 ·
Have a look at the video below, at around 4:00 he removes the cpu heatsink & fan, doesn't look very difficult and you can replace just the fan. You should be able to find a new Cpu fan on Ebay.

 
#7 ·
I saw that video already. It didn't help, because the screws are a bit too impossible to get out.

Anyway, a little update: I just started this thing up again this morning. Here's the interesting thing: when I first started it up, I could hear the CPU fan running at full force. That only lasted for a few seconds, and it hasn't come back on since. For now, the cooling pad I bought a few days ago is doing a good job of supplementing it, but I really want to get this solved.
 
#9 ·
I saw that video already. It didn't help, because the screws are a bit too impossible to get out.
Have you tried getting it out yourself? Use a slightly bigger driver and it should achieve enough torque to get the screw out. I recommend purchasing an iFixit kit or similar product to make it easier to take electronics apart. Still-your fan isn't working as it should even if it fired up for a few seconds.

Furthermore, as Jim stated above, there may be some software to control fan speeds. If you can't find any preinstalled, you might have some luck with SpeedFan; although, in my experience I haven't got the fan control options to work on any of the computers I've tried using it on.
 
#8 ·
Did you reinstall the OS, drivers, and software or are you simply using it as you received it?

Most laptops ship with software that controls the fans. I'm not familiar with Alienware, but as they are Dell, there should be software involved.
 
#10 ·
As I linked in the OP, I got Speedfan the day I got this thing. I've tried to use it to control the fans, but every tutorial I've found didn't help. It might be that the motherboard isn't one that SF is compatible with. (And don't bother asking me what kind - SysInfo only says it's an Alienware brand and nothing else.)
 
#13 ·
The video actually is mine, but it doesn't explain much regarding this problem. That video was about having trouble replacing the GPU (it's locked in by these) - another problem for another topic, I guess.

I've been using Speedfan long enough to tell what's going on here. The fan is on, but runs at the same slow speed constantly, never speeding up or slowing down to accommodate for the changing temp. No matter what the temp, there's only a very small current coming out of the vent.
 
#14 ·
Ok then, things you can try :-

Try running Prime95 or similar to run the Cpu at 100% and monitor the temps with SpeedFan. If the fan doesn't speed up you know there really is a problem. I would try this even though you say you know it doesn't speed up, just to verify this.

Fit a new fan, the present one could be faulty.

Check to see if there is a software program to control the Cpu fan for that laptop, should be on Dell's website.

Update the Bios but only if there's an updated one that addresses fan issues.

It's hard to tell if this is a software or hardware problem so you should try everything you can.
There could be a fault with the Cpu temperature sensor, just a guess and I hope I'm wrong because I don't think that's repairable and you would have to replace the motherboard.
 
#15 ·
Okay, let me correct myself here. Just now, I checked the bottom of the laptop, and noticed something interesting: it's just the corner that gets heated up, as in the spot around the grill piece. The spot around the fan itself is perfectly fine temp-wise (though oddly, I still don't ever hear the fan running). Interestingly, it's also stopped running up to 80C+ whenever the comp comes under load. It still runs relatively hot, in the 55-65 range, but not to a point where it actually damages performance.

Another thing I figured out about my own stupidity is that the heated area in question isn't the CPU. It's the GPU. Derp.
 
#16 · (Edited)
That probably means the CPU fan is ok and doesn't need to come on but I would still try running the CPU at 100% and see if the fan comes on then. If you monitor the core temp(s) with Speedfan's chart tab it's easy to see if the fan kicks in, you should hear it too.

I think it has a separate GPU fan so presumably that is working.

Looks like you may be in luck and everything is working properly after all.

(Disregard the part in my previous post about the CPU temp sensor, it's built into the CPU so you wouldn't have to change the mobo ! ).
 
#17 ·
Despite what the title says, this is more complicated than it would seem.

Yesterday, I opened up the M15X and unscrewed the CPU fan assembly in an attempt to figure out what was causing an unrelated issue. I couldn't figure much out, so I put it all back together, tried to run the laptop again, and got...this:



That's NOT a good sign. I ran a Google search on it, and from what everyone says, those three blinking lights indicate a motherboard problem. I, for one, know very well this isn't a problem limited solely to the motherboard, seeing as the thing was running (mostly) fine before I did the whole CPU operation.

What's REALLY ODD about this is that I didn't remove the CPU core itself. I only unscrewed the fan assembly, leaving the actual processor unit still attached. The only thing that came off of the CPU itself was a little bit of thermal paste that had gotten stuck on the fan piece. It's also compounded by the fact that I didn't even unplug the fan, only unscrewed it, and left the cable still attached. That being said, I have literally no idea what could have caused this. Help?
 
#21 ·
The only thing that came off of the CPU itself was a little bit of thermal paste that had gotten stuck on the fan piece. It's also compounded by the fact that I didn't even unplug the fan, only unscrewed it, and left the cable still attached.
Yeah...
 
#22 ·
It could be that tugging on the fan assembly atop the CPU unseated it. You may need to reseat the CPU, but I'm not entirely sure if I'm even correct here. I know desktop CPUs use a retention arm to hold it in place, but I'm not sure what a laptop does to hold a CPU in place.
 
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