Solved Laptop Fans Unresponsive After Paste Change

Hi, I recently cleaned out my Acer Predator Helios 300 (PH317-51), which had not been opened or cleaned since its original purchase 4 years ago in 2017. I removed dust from fans and heatsink, applied new thermal paste, and replaced stock thermal pads with higher quality ones. However, during reassembly, I plugged the fan connection to the motherboard in upside down by mistake, and even after reopening the machine and plugging them in the correct way, the fans are just completely non-responsive. My machine has a built-in software called PredatorSense that lets me control the fan speed and monitor CPU/GPU temps. The fans remain at 0 rpm even when set to max, and are dead silent at any temperature.

I don’t think the issue at heart is the fans themselves, because they were working fine beforehand, and I didn’t use any liquid to clean them. I first removed the heatsink from the motherboard, and then the fans from the heatsink. Then for cleaning, all I used was a can of compressed air (holding the fans with my finger so they don’t spin), and I used a small blunt edge to scrape off some grime in between fan blades, kind of like flossing. At any rate, even if the fans are faulty somehow, they should still spin (or try to), and you’d hear some noise or they’d be too slow to be effective, but they wouldn’t be dead zero and unresponsive to my predatorsense.

My best guess is that by forcing in the plug the wrong way, perhaps I damaged the connector in some way (either the hole or the plug that goes in) or I somehow shorted something on the board itself (or maybe the former causes the latter).

I’ve scoured the internet for a similar scenario and possible solution in vain. I think I only found 1 or 2 guys in similar situation on some forum, with no apparent solution.

I do have a multimeter at home, that my brother used for a college class, but I don’t think I’ll attempt trying to find, much less do anything about a shorted circuit. I mean, I screwed up even the simple paste change operation despite a mountain of online support guides, disassembly videos, and taking my time to familiarize myself with everything. I’m no electrician and I’d probably just do more damage (thankfully everything else seems to work fine, though I’ve not actually tested the dedicated GPU, for obvious reasons of overheating).

So I would be happy to have a professional try their hand at this, but I imagine the cost would be hundreds of dollars now. I don’t even know who to turn to, since most “pc repair” people only do simple operations like “data recovery” = they unscrew the back panel and take out a HDD or something. They don’t have the experience or tools or even care to take risk for fixing a motherboard. The tech world has a culture of dispose and replace everything because it’s all so inexpensive right now.


Anyway, sorry, this became quite long, but if anyone has any useful suggestions, I’m all ears. I don’t know what to do, my brother (always been a tech kinda guy, studying computer engineering major) is equally out of ideas, and I can’t find any help online. Maybe somebody knows a good tech repair service I can contact? Or perhaps someone with experience in the field can guide me if there is some DIY solution I missed or overlooked.

Thanks for your time and any help you might offer.

Update: After writing the post I thought, hey maybe I should double check that the GPU works. So today I powered it on and used an external fan pad I had lying around (which was useless, as expected), and played about 5-10 minutes of Doom 3 (and switching back to Predator Sense to make sure I stop before temps get too high). Something interesting occurred. Now, I know for a fact the game, which was quite graphically intensive when it came out in 2004, would not be able to run on the integrated graphics chip alone, at least, certainly not at a silky smooth 60 FPS (my laptop monitor’s refresh rate). It must be utilizing the dedicated NVIDIA GTX 1060 graphics card. However, in the aforementioned Predator Sense application, there are simply no readings from the GPU at all.

For the CPU, fans don’t spin, but I can still read what the current temperatures are, and the percentage utilized currently (e.g. 85 degrees Celsius, using 57% of CPU. I made those numbers up, but it would show something like that).

For the GPU, it shows neither the temperature not percentage used. And of course, fans don’t spin here either, which goes without saying.

I thought this new piece of information might be useful to mention, might help solve the puzzle.

Thanks, PeterOz. I’m not sure if I have an extra laptop fan. I do have some old computers, but I’ve been using my old cheap laptop from 2011 as a temporary backup. I don’t want to risk doing anything to that one, since it’s way past it’s expiration date as it is. I’ll see maybe if I can find one and try that.

What did you think of the PredatorSense app? Why would it be unable to read measurements from the GPU but able to read CPU temps/ % used? I think I might try reinstalling the software, on the off chance it might help.

Any advice for properly connecting a different fan (3 pin vs 4)?

Hi PeterOz,

Yeah, I found that online too. I think the fan is $25-$30 depending on the vendor. The model of laptop is not exactly mine, but the fan looks identical to the one I got (I will double check that against photos I took during disassembly) but it looks right, like it would fit inside.

Thanks again for your support.

As an Update 2, I wanted to add that I tried uninstalling and reinstalling the Predator Sense software. It now correctly displays the GPU temps and usage, but alas, it did not fix the fans. (Didn’t really expect it to, but partial success I suppose.)

I think Amazon offers returns, so if it’s not the fan at fault, I can just return it.

I’m unfamiliar with the KISS method? What’s that?

PeterOz said:

Bonus

Keep It Simple Stupid - Not saying you are Stupid it is just a saying like PEBKAC

Click to expand...

Ah, thanks. (I don’t know what PEBKAC is either, sorry)

Okay so I found and bought two replacement fans from ebay (brand new obviously). They’re the same as the Amazon ones but slightly cheaper, also free returns. They were $10 each, but I was a bit disappointed that I could only find ones with plastic blades, as opposed to the more effective metal fans which came with my machine. Otherwise the model is identical. But if these replacements work, I will be very lucky and not complaining over a couple degrees here or there.

The fans are expected to arrive in a week. I would appreciate it if mods could keep this thread open while I wait for them to test them out.

My replacement fans came in today. I’m going to change them out. Here’s hoping this does the trick. I’ll let you know how it goes.

Tangential question: Since this was also my first thermal paste change, and I am now opening it up again for the first time since then, did I apply the right amount? I did the pea method, and I think it seems to have expanded to cover the CPU/GPU, but what do you think?
Also, should I clean/re-apply the thermal paste before re-assembling, or is the existing paste I put a week or two ago fine? @PeterOz

Yes, thank you for the reply. I guess I will use Kryonaut’s recommended method this time (using spatula they give to spread it out).

My new fans do not have that little white dot, so I double checked with my original fans and videos online: the side with the white dot (that goes up) has these 4 little golden pins. I marked that side with a small black sharpie dot for future reference, but also remembering pins side goes up.

Thanks for your double check reminder. As I was typing this I realized I put one of the sharpie dots on the part of the plastic that goes in the motherboard. Baaaad idea. I used the isopropyl alcohol and coffee filter papers to wipe it off completely, now putting it on the little end sticking out (which is what it’s like for the white dot on my originals).

New fans:


Original Fans:


As you can see, the side with the pins has wires RED, YELLOW, BROWN, BLACK, from left to right.

Hi, @veeg @PeterOz

Sorry for the delay.

I applied the thermal paste using the spatula/spread method today. Is this the right amount, or too much?

Well I went ahead and re-attached heat sink anyway. I plugged fans in as said above. I noticed a bit of weird substance on one of the motherboard components.



It’s the PL7103 and to lesser degree PL1801. I cleaned that gunk off with a tiny bit of the same 91% isopropyl alcohol on coffee filter paper. What was that? Some spilled thermal paste? I think I remember seeing it too before when I opened it up the last time. Or, since it’s in proximity to the fans, could it be the part (if any) that got damaged? We shall see.