XPS 15 (Haswell) Owner's Lounge

Discussion in 'Dell XPS and Studio XPS' started by mark_pozzi, Oct 23, 2013.

  1. jphughan

    jphughan Notebook Deity

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    Well most XPS 15s come with 8.1 non-Pro, so unless you have one of the few that came with Pro, chances are the ISO you tried to use could only install Pro and not non-Pro, which would explain why you kept getting prompted for a product key that kept getting rejected.

    You might have to click the "Show options that aren't currently available" link in the Advanced Power Options window to reveal adaptive brightness, fyi. But it's definitely on the Dell image since I found it before I did a clean install.
     
  2. dragontas

    dragontas Notebook Enthusiast

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    Turn up the volume in the video to very loud! You will hear exactly the interferences that are shown in the video. Take a SMD stetoscope and listen to the coils. This is the one making the noises.

    2R2 is the usual description for the inductivity in SMD Coils. I used a scope to measure the frequencies in the five coils. Only this one has changing frequencies, that fit exactly to the whining noises.

    The frequencies vary dependent on the load. If you have some read/write activity on the SSD or the battery stopped loading there is this activitiy on this coil.

    I contacted them. They did not react. If i would have two more samples i would investigate two weeks to solve the problem. We should give it a try with some epoxy.

    The waveform is the voltage on the coil. If i resize it you will see a digital signal. Some PWM (Pulse Width Modification) chip is generating this signal dependent on the load. (SSD activity, Battery charge/discharge, CPU state). Turn up the video volume and you will see exactly what you hear.
     
  3. Zoomsday

    Zoomsday Notebook Consultant

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    Yes, I can hear the noise. But I thought the scope you used was an electrical scope. So you get the conclusion that the inductor is causing the noise by the fact that there's a noise and the voltage on this inductor is non-ideal? I don't think the reasoning is that convincing.

    But again, even if you are right that the frequency on that inductor is changing, it might be a symptom of some other design issue rather than indicating that this power inductor is itself defective. Thus, switching the inductor might probably not going to help.
     
  4. dragontas

    dragontas Notebook Enthusiast

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    This coil is causing the noise. As already written you can use a stetoscope to identify the noise. The osciloscope is only a second proof for my assumtption, as this is the only coil with changing frequencies that fit to the noises. I do not know if the frequencies are ideal or non-ideal. But from the view of an electrical designer it would be very simple to check this. The design of such a regulator is usually first done in a simulation. Then a prototype is checked vs. the simulation. If it doesnt. fit the simulation is wrong and the design aparment has to do some debugging with theyr circuit design programm reseller.

    I do not think that the coils are faulty. I think DELL should have used epoxy filled coils. I also think it should be possible to fill this coils with epoxy afterwards. I i would know which coil this is exactly i would take this coil in parts. When i know how they are built i would open mine on my notebook and fill it with epoxy. This is only a fast fix for the user!

    Further i think the electrical characteristics of the coil are good from the electrical designers view. But for some unlucky reason it is whining with this type of coil. I am not sure if the people at DELL are deaf. I do not think so.


    My no.1 assumption for the real reason of coil whine is a mismanagement between DELL's design apartments. The electr. design appartment doesnt want to have the fault on theyr side. But i am reaally wondering how it could happen that such a noisy circuit design could go into mass production :D ... Somebody is sitting in the DELL's design apartment in a managment position which doesnt want to see :D....
     
  5. dragontas

    dragontas Notebook Enthusiast

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    20140410_213244.jpg

    Some pics of that


    20140410_213700_small.jpg

    It is the same signal captured with different frequencies.
    The upper one with 2.5us and the second pic with 0.5ms.
    The noise-resonating freqency of the coil is somewhere between
    2khz and 14khz and more...

    The best thing would be to take this coil as a single part and reprocude sound creation :D
     

    Attached Files:

  6. Mihael Keehl

    Mihael Keehl Notebook Evangelist

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    Wait, so does this "coil noise" effect every laptop that Dell is selling?

    I was just about to place an order.
     
  7. someguy00

    someguy00 Notebook Consultant

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    It doesn't affect everyone. I am fortunate to have received an XPS 15 without any kind of coil whine. Perhaps I have just been lucky? It would be interesting to make a poll to see how prevalent this problem is. I receive my XPS in February (ordered in December).
     
  8. loui100

    loui100 Notebook Geek

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    I've had my motherboard replaced 3 times. Each one (4 in total) had coil whine. How unlucky can I be?

    Had it been a rare problem, it wouldn't be an issue at all. Everyone would get their units repaired/replaced, and no one would go as far as to make all this fuss, invesitgation etc.
     
  9. daFacts

    daFacts Newbie

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    I received mine on 3/27 and i'm glad I don't have the coil wine either.....I have a mdi tier model.
    however, I don't understand why the camera basically turns off in low light situations...it's a bit annoying as every HP that I've owned seems to work in even complete darkness.
     
    adlerhn likes this.
  10. loui100

    loui100 Notebook Geek

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    Hmm, interesting. Maybe the mid-tier models are not affected?
     
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