# Acer Aspire 9420 and sensors

## i92guboj

Hi.

I have been struggling to get this working for a few weeks, so I thought it's about time to try to get some help  :Wink: 

I have one of those laptops. It works fine but lately it has started to make some strange noise on the right fan. It happens like 2 or 3 minutes after powering it on. It lasts like 30 seconds, then it goes quiet again, and it usually stays quiet until I turn it off again, even with high cpu loads.

The cpu temperature is fine, so I am not worried in that sense. But I'd like to see how the fans spin up or down before trying surgery on this thing. My main concern is that the fan engine might burn if the fan is either locked or loose.

Now, the bit I need help with is that I an unable to get any lecture from the fans. Gkrellm can't find any, and lm_sensors only reports this:

```

$ sudo sensors

acpitz-virtual-0

Adapter: Virtual device

temp1:        +50.0°C  (crit = +96.0°C)

temp2:        +61.0°C  (crit = +111.0°C)

coretemp-isa-0000

Adapter: ISA adapter

Core 0:       +57.0°C  (high = +100.0°C, crit = +100.0°C)

Core 1:       +59.0°C  (high = +100.0°C, crit = +100.0°C)

```

As you see, I get lectures both thru acpi and the intel coretemp driver, but nothing for the fans. I have enabled all the i2c modules in the kernel (as modules), and I have also enabled the acpi kernel option for fans (module name "fan").Nothing has worked so far.

In the internet I am only able to find a couple of useless Ubuntu forum threads about this concrete model. If anyone has an idea on what else to try I'm all ears.

Thanks  :Smile: 

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## Roman_Gruber

AFAIK a notebook should be cleaned every six months. if its a cheaper model or brand it is necessary more often. cheaper brands also sometimes ship half defective fans also. Personally (sorry) i think acer is such a brand.

my usual solution is to fire up a very new livecd and check if the sensors are there and if you can read them out there.

as these days there is udev/ eudev / systemd taking over and for myself it is not clear in which direction the paths goes. Therefore I want to point out, in the old days it was much easier to see how and where to read out the build in sensors.

some boards are not able to read out the sensors anyway.

summary, get a very new livecd with newest kernel and userspace tools and try it that way. or build the newest kernel with every module build in and check, but i can not guarnatee the success.

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## i92guboj

 *tw04l124 wrote:*   

> AFAIK a notebook should be cleaned every six months. if its a cheaper model or brand it is necessary more often. cheaper brands also sometimes ship half defective fans also. Personally (sorry) i think acer is such a brand.

 

I agree in every word, this one I bought because of the price, nothing else. I don't like brands starting with A, anyway. I won't give names  :Laughing:  :p

 *Quote:*   

> 
> 
> my usual solution is to fire up a very new livecd and check if the sensors are there and if you can read them out there.
> 
> 

 

Yes. I was thinking that's about time to check if knoppix is still alive and kicking. Well, I'll report back if I can find something.

However, I have little hope. Yesterday I updated the BIOS to the latest version (from 1.13 ro 1.24 or something like that). It took quite some work because the only exixtent flasher is a Windows tool which won't run even in FreeDOS. So I had to make a Windows livecd and put the flasher on it, and then use the "force" option because it wouldn't let me flash still due to some silly power or battery check. The thing is that even after that, there's nothing about fans rpm in the BIOS. However, there's no info about temperatures either and they are read ok under linux, so I don't know what to think.

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## Roman_Gruber

 *i92guboj wrote:*   

> Hi.
> 
>  It works fine but lately it has started to make some strange noise on the right fan. It happens like 2 or 3 minutes after powering it on. It lasts like 30 seconds, then it goes quiet again, and it usually stays quiet until I turn it off again, even with high cpu loads.
> 
> Thanks 

 

could be a cheap fan with not proper ball bearings. or something else. sometimes you may think it is a fan but it can be an electircal coil too or some transformer. if they want to save money they build in quite cheap coils / transformers which generate sounds. you may hear something like that when you power up a device sometimes. 

Well if the fans are rotating in their proper way and they are free of dust. the hole air path should be free of dust. try to rotate the fans when they are off, you should see if their bearing are broken.

i do not expect anything from that brand when you give it away for maintanence as they will say probably won*t fix. 

As long the fans are rotating at their desired speed and the air path is free of dust i would not worry that much. 

if it is an older modell lets say over 12 months you may apply new thermal paste on teh cpu and the gpu. cheap brands, even ASUS uses cheap thermal paste. new quality paste reduce the temperature always too.

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## i92guboj

 *tw04l124 wrote:*   

> 
> 
> Well if the fans are rotating in their proper way and they are free of dust. the hole air path should be free of dust. try to rotate the fans when they are off, you should see if their bearing are broken
> 
> [...]
> ...

 

Disassembling laptops is not a new thing for me, I do an average 2-3 of them every week as part of my job, it's just that I am pretty short of time at the moment that's why I wanted to know the fans rpm if possible without having to open the critter. That's exactly the problem. I can't get that lecture so I don't know if the rotation ratio is ok. The temperature is ok for this kind of cpu, this season and the area where I live.

 *Quote:*   

> 
> 
> if it is an older modell lets say over 12 months you may apply new thermal paste on teh cpu and the gpu. cheap brands, even ASUS uses cheap thermal paste. new quality paste reduce the temperature always too.

 

For now there's no need to do that, since, as said, the temperature is quite fine. And the noise if not the kind of noise that you get when a laptop is overheating. I can distinguish from a ten miles distance  :Laughing: 

I think that this motherboard just lacks the fan sensors.

BTW, the machine is a second hand one. It's in a very good state and it was really cheap, which is why I bought it. It serves its purpose quite well for the price I payed for it. And, in any case, I was in a rush since I had to complete a work and couldn't find anything better.

I wouldn't EVER buy an Acer machine afresh on a shop. I am really picky about the hardware I buy if I am going to spend good bucks on it.   :Laughing: 

By the way, thanks for all the ideas  :Smile: 

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## destroyedlolo

 *i92guboj wrote:*   

> I don't like brands starting with A, anyway. I won't give names  :p

 

Amiga was the only A company to take in account   :Laughing: 

About the noise, I got a very old laptop (about 10 year old, used 10 to 14 hours a day), which is doing the same. Only at startup. In my case, I guess it's only mechanical and due to the low temperature compared to a normal working one (thermal expansion stuffs ...).

As long as it stops when the CPU reach it's "usual temperature", I don't worry.

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## Ant P.

The usual answer here is to boot with acpi_enforce_resources=lax - it might make your fan sensors accessible but even that doesn't always work. For ACPI, especially on notebooks, brokenness is the norm.

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## Navar

Without hearing the noise, my guess from your description would be it's a sleeve based bearing fan.  Startup noise is generally due to friction drag on the bearing and motor versus the amount of power being applied (and in this case, probably having trouble getting going).  You could try a very lightweight oil, particularly sewing machine oil, just a tiny amount once you've exposed the semi-sealed bearing area (remove tape, plug, etc. on back of fan).  But as you probably know, especially since it's Acer, it's most likely sleeve bearing and eventually junk.  The alternative being bearing based, which can work under high load and rpm for a long time, but can produce significant high frequency running whine noise over time.

Ideally, see if you can source a replacement.  There is the possibility of burning out the fan header supplying the power due to the fan failing.

Oh and contrary to some of the advice, big kernel changes a few years back (from 2.6 days) caused grief for older sensor readings and why lm sensors will flat out fail at times (if this is older hardware).  What Ant said applies in a workaround to help deal with the matter, but you may well want to try an older distro release livecd for testing (circa 2008-10 should work), rather than anything new.  I've got an A7M266 mainboard that has been a pain for this.

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## i92guboj

 *Ant P. wrote:*   

> The usual answer here is to boot with acpi_enforce_resources=lax - it might make your fan sensors accessible but even that doesn't always work. For ACPI, especially on notebooks, brokenness is the norm.

 

Yup, it didn't work. I conclude that this laptop has no support for that. I haven't tested any other OS though. But no linux livecd can read the fans and there's no info about them in the BIOS either, so...

 *Navar wrote:*   

> 
> 
> Oh and contrary to some of the advice, big kernel changes a few years back (from 2.6 days) caused grief for older sensor readings and why lm sensors will flat out fail at times (if this is older hardware).  What Ant said applies in a workaround to help deal with the matter, but you may well want to try an older distro release livecd for testing (circa 2008-10 should work), rather than anything new.  I've got an A7M266 mainboard that has been a pain for this.

 

I will, just out of curiosity. But it won't solve anything even if that works. If I find something new I will report back. 

Thanks everyone for all the suggestions  :Smile: 

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## i92guboj

So, no trace of the sensors.

I found -finally- a second hand replacement for my fan on a local store, and the noise has gone. For now.

A big "thank you" to everyone who contributed to the thread.

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