HP ProBook 4530s - Fan always on - Help with DSDT editing or NHC ACPI module

Discussion in 'HP Business Class Notebooks' started by jhonq, Apr 14, 2012.

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  1. jhonq

    jhonq Notebook Guru

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    Hello, i have this 4530s (2350m + hd3000) for about a month and the fact that the fan is allways on is bothering me. I have the latest bios - F.25, released on 27 mar 2012.

    On this model the fan starts when cpu temp gets to 40C and will turn off at 31C. The problem is that it will reach 40C in a minute after login but can't ever drop to the point where it turns off. (Had to take cover off, hold it outside in the cold to test the fan off temp :D ).

    Here are 8 pages of discussion on this issue where i have tested when the fan increases/decreases in speed. There is tool made for thinkpads that is compatible with this HP, as it writes values to the same offset 47 of the EC. This only helps in locking the fan at the lowest speed posible and somewhat lower noise, as the fan would wake and stay at a higher speed if left alone. :mad:

    That thinkpad tool can turn the fan off but only when temp is under 40C, so this is not helping much.

    Here is how the fan works:

    "
    - 0-39C, state is 255 (off)
    - 40C, state is 82
    - 50C, state is 74
    - 60C, state is 65
    - 70C, state is 59
    - 80C, state is 49

    - Drop to 70C ---> fan state 59
    - Drop to 60C ---> fan state 65
    - Drop to 50C ---> fan state 74
    - Drop to 40C ---> fan state 82
    - Drop to 31C ---> fan state 255

    - Using tpfancontrol or acfancontrol to write decimal values at offset 47, we have the 0-255 range:

    -------255 state - Fan OFF

    -------128 state - Slowest fan setting other than off (129 to 254 make the fan sound exactly the same as 128 state). This state is never activated by the DSDT! The fan starts at a higher speed (82 state)

    -------127->0 - The fan gets louder and louder the lower the state is set in this range"


    The only "fix" for this insane issue is to get help from someone who understands how DSDT works to edit it or to make an ACPI module for NHC. I had a go with this ths tool and it seems to work with the 4530s. The problem is it needs a working ACPI module. This needs to be written from scratch. I had a look at a step by step guide for an Asus notebook and it seems doable for someone who understands this language, but i got stuck as only one other method is used on the 4530s dsdt.

    I think that having a working NHC ACPI module is the best option. The user can change the temp when the fan is on/off, what speed at what temp etc.

    This is the final step of the Asus tutorial and the fan control is amazing! :eek:

    I would also be very happy if someone could help with dsdt editing so that the fan does not start at 40C, but at 65C or something like that and turn off at 55. Basically just move the temps 20C higher than the default table!

    If only the cpu temp could be tricked in having an offset of 20C lower... :cool:

    Here is my DSDT extracted from the latest bios and a screenshot from NHC where a value of 31 (fan off temp) can be seen...
     

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  2. BurtaN

    BurtaN Notebook Guru

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    This sounds very interesting and the tool seems to work with my Elitebook 8460p as well. However, the CPU temp is not read correctly.
     
  3. hhhd1

    hhhd1 Notebook Consultant

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  4. jhonq

    jhonq Notebook Guru

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    You talk about tpfc? Thinkpads control fan speed from the same byte of the EC as some HP models, so this helps us a little. It's use is to lock the fan at the lowest speed posible. Too bad it can't lock the fan in the off state! :mad:
     
  5. hhhd1

    hhhd1 Notebook Consultant

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    the problem is that the fan is really inefficient, i've compared it to few other laptops, and it seems that many other fans push out allot more air while making significantly less noise,

    for the amount of air being pushed out at the lowest speed it should not be audible, ..

    i would love to find a silent fan replacement that will work on this laptop.
     
  6. hhhd1

    hhhd1 Notebook Consultant

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    we need our own tool coded for the 4530s,

    if someone knows where to start i'd be willing to spend some time trying to code a tool like TPfancontrol tool but dedicated to this laptop.
     
  7. jhonq

    jhonq Notebook Guru

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    There is a tool written by a German friend, for all HP notebooks that control tha fan using the EC - [AML] Lüftersteuerung per ACPI - Seite 3 - ComputerBase Forum
    It's not available to the public yet, as he thinks more work is needed. I've been testing and it works fine.

    The problem is the author can't get past the "fan can't be off at over 40C" limitation. Don't think anything can be done about this if HP doesn't provide EC documentation...

    I've been asked to not make it public, so i will try to respect that. hhhd1, if you can help with coding, provide an email or something to make the latest version availabe for testing etc. Maybe you can register at the german forum and contact the author for the source (?!).
     
  8. hhhd1

    hhhd1 Notebook Consultant

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    Sounds good.

    i'd be really interested in contributing to the code, and maybe try to find a solution for the issue of "fan can't be off at over 40C".

    i'll register at that german forum, .. and send you my email in a pm.
     
  9. hhhd1

    hhhd1 Notebook Consultant

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    i have checked the nhc screenshots guide, and after doing some searches, i found the acpi language specs in here ACPI

    and the language that is used to create modules in nhc i think it looks like C# ,

    still looking.
     
  10. hhhd1

    hhhd1 Notebook Consultant

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    a little correction, 255 does not mean fan off, 255 means leaving it auto controlled, and when temp is less than 40, the fan auto level is 'off'

    if you set it to 255, and stress the cpu, the fan will keep changing variably.
     
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