Hi all,
 
My CPU fan has started acting up on my 2.5 year old SC17. It's making a bit of noise, and at one point, actually stopped spinning. Removing the back and brushing/blowing as much dust as possible has got it spinning again, but it's still making an audible noise that is concerning. Additionally, the CPU fan does not spin as freely as the GPU fan. I'm at a point where I think I need to, at the very least, remove the fan to clean it, if not outright replace it.
 
Are there any instructions somewhere on removing/replacing the cooling fans? I tried removing just screws on the fan itself, but it's looking like I might have to remove the entire cooling unit and that was a larger amount of effort I wasn't willing to just wing on the fly without knowing what I might need to have on-hand to successfully put everything back together.

I found some replacement fans on Amazon as well, priced at about 50 dollars. I noticed a couple different brands, although I'd be hard pressed to tell the difference on the fans themselves based on the pictures.
 
I haven't ordered anything yet. I'm also unclear if I need to ensure I have anything else on hand, such as thermal paste or anything else I can't think of. I did remove the four screws around the fan, but it appears to be covered by the rest of the cooling unit. Looking at the pictures of the replacement fans, it appears that that fans aren't fully enclosed and that the side with the open face is facing the bottom of the laptop, with the closed face side positioned up towards the motherboard/hardware. So, this means that the cooling unit covering is actually providing the covering for the fan to help enclose it. I wish I had taken some pictures when I had it open, it'd be a whole lot more clear to explain it.
 
Anyway, all that to explain that indeed, the surrounding assembly is also covering the fan and I'd have to remove it. What I'm not really sure about is identifying all of the related fasteners I need to remove (I noticed some, but probably not all), and if there are any other things to keep in mind when removing and later reinstalling the cooling assembly.

I wish I had taken pictures. On the other hand, I might crack this open again soonish so maybe I'll do that this time.
 
So, I ended up ordering replacement fans I found on Amazon. I also ordered thermal paste just in case since I was uncertain if any was used in between the components and the heat sinks/fans (and there was, so glad I bought that - it was cheap insurance anyway). You also need some specific bits to remove the bottom cover and different bits to remove the entire cooling unit (I ended up just getting a nice IFIXIT computer repair kit). I don't recall the exact bits I used, but I think some of that information is already floating around here or on reddit.
 
Anyway, once you pop the bottom cover off, the entire cooling unit is plainly visible. In order to access the fans, you'll need to remove the cooling unit because it's covering the fans from your direct access. However, the cooling unit is itself covered by some plastic trim that double as circulation vents. This trim sits underneath the laptop screen hinge. Once you remove those, you should then be able to remove the cooling unit. The cooling unit itself is attached to the primary board with some spring-tensioned screws. Loosening them allows you to remove the board, although be a bit careful as there is thermal paste where the CPU and GPU are. With the unit out, the fans are attached to the cooling unit with some tiny philips screws.
 
After that, you can remove the fans and install the new ones. Since the fans I bought came as a pair, I replaced both even if my GPU fan seemed fine (I've kept both original fans just in case). Then clean the old thermal paste, apply new paste, and reattach the cooling unit and everything else.
 
Where I messed up, I think, is that I'm not sure I added enough thermal paste. I feel like my fans spend more time at max RPM more often than the originals did, and I wonder if not using enough thermal paste has interfered with the chips' capabilities to evacuate heat. So, I've been thinking about opening everything back up again to ensure/fix that enough thermal paste is used, and hopefully see better results. It's been in the back of my mind for a few weeks now, so I think I'll probably end up doing that soonish when time allows.

Hey, Having issues with intermittent fan noises. Which fan is the one on the left side with the keyboard facing up?

"Where I messed up, I think, is that I'm not sure I added enough thermal paste. I feel like my fans spend more time at max RPM more often than the originals did, and I wonder if not using enough thermal paste has interfered with the chips' capabilities to evacuate heat. So, I've been thinking about opening everything back up again to ensure/fix that enough thermal paste is used, and hopefully see better results. It's been in the back of my mind for a few weeks now, so I think I'll probably end up doing that soonish when time allows."
 
Hopefully a reapplication of thermal paste fixed the possible heating issue and hopefully not just being caused by using an oem replacement fan that doesn't read speed properly.  This Chinese stuff can really be a crap shoot on quality and usually they are the only source for some parts.
 
Please let us know.  Also thank you so very much for posting such useful information as you have about replacing the fans because it really helped me out.