mandag 29. september 2008

Patching the DSDT table

How to reduce fan noise on your HP notebook

Warning: This procedure has the potential to damage your computer!

This procedure involves patching your DSDT table and altering the fan speeds specified in the DSDT table. (You may read more about DSDT in Wikipedia). This procedure has to be repeated every time you update your BIOS.

Download equus.exe (right upper corner) to extract the DSDT table from registry (raw binary).

You need the following software to compile:
 Microsoft ASL Compiler (Latest version)
You may download it from

For monitoring purposes you may use:
 HWMonitor (Recommended)
You may download it from

Follow the instructions beneath:
1. Install Microsoft ASL Compiler and copy asl.exe from the install directory to C:\ACPI. (Create the C:\ACPI if necessary)

2. Copy equus.exe to C:\ACPI

3. Run equus.exe. You will be prompted to enter the subkey path. This is the directory where your DSDT table is loaded in the registry. Easiest way to find it is to do the following:
a. Run -> regedit
b. It is usually located approximately on the same directory. E.g:
c. Once you find the subkey, right click to "copy key name" (or something).
d. Paste the directory into equus command window

4. Now you are prompted to enter the key name. This is the actual key we are looking for where the fan speed information is loaded. The key we are looking for is located within the subkey you found above. It is a REG_BINARY and usually named "00000000". Thus, just enter 00000000

5. If everything worked, a file named dsdt.aml should show up in C:\ACPI. If the file is not there, the directory or the key name you entered is not valid. (The software just skips on error)
6. Run command prompt using "Run as Administrator" and type the following:
a. cd C:\ACPI
b. copy dsdt.aml dsdtorig.aml (Creates a backup)
c. asl /u dsdt.aml

7. If everything went fine, a new file named dsdt.ASL should be created in C:\ACPI

8. Open dsdt.ASL in notebook. It should look like a software code. Now is the tricky part. You need to find the fan speeds. However, numbers are written in something like hexadecimals. (You may read about hexadecimal numbers in Wikipedia).

9. From now on you need a converter to convert decimal numbers to and from hexadecimal. You may use this webpage:

10. You know that at some point your fan hits 100% of its speed. The fan speeds are given as percentage in the DSDT table. In hexadecimals 100 is 64. Thus, in the dsdt.ASL file 100
should look like 0x64. Moreover, you know that at some point the fan stops. In hexadecimal 0 is 0. Thus, in the dsdt.ASL file 0 should look like 0x0

11. In the dsdt.ASL file, simply search for 0x64. You are looking for a "list" of numbers that starts with 100 and ends with 0. The "list" should contain around 5 numbers, all in 0x(hexadecimal) and ranging between 100 and 0 in descending order.
a. E.g. ( The text above and under may be different in different systems)

12. Change the fanspeed as desired using the hexadecimal converter
a. E.g:
i. 100% -> 0x64
ii. 80% -> 0x50
iii. 45% -> 0x2d
iv. 35% -> 0x23
v. 0% -> 0x0
b. You need to be sure that you are actually changing fan speeds and nothing else!

13. Save dsdt.ASL

14. Enter the following in the command prompt window
a. asl dsdt.asl
i. You may get some warnings, but if you haven’t touched anyting beside the fan speeds, just ignore them!
b. asl /loadtable dsdt.aml

15. Now reboot and enjoy the silence

Remarks: Do not change the top two fan speeds as they will act as "buffers" given by the manufacturer. This will prevent you from burning your system if you overdo the "silencing".
Your system will now run slightly hotter. For a notebook with discrete graphic accelerator 60 C is an acceptable idling temptratur.

If you want to recover back to your original DSDT table, just type this on the command prompt:
cd C:\ACPI
asl /loadtable dsdtorig.aml

This method was tested on Vista 32-Bits and HP Compaq nc8430. This method may work on non-HP systems, however the author has no experinece with non-HP system.

Please try the method and give me your feedback.

77 kommentarer:

darkwolf sa...

I'm from Bulgaria.
My name is Zdravko Genov.
I like very much your idea for Patching the DSDT Table but I need little help!

I have HP Compaq 6730s

I have:
Name(CPFS, Package(0x6)
(it must be the right code)

The Problem:
I was very confused because my fan always stars (when Windows XP stars) and stays constant (80-90% of the time) on 50 %(0x32) - the temperatures are between 35 and 45 degress very often - so cleary I NO NEED 50 % fan speed!

After I perform "Stand by" it somehow jumps and stay on "20%"

The fans must stars on 50 % after 50 degree but it happen only sometimes!

Information about the temperatures:
I'm 100 % sure the fan stars to run on "0x3c" 60% - when the temperatures hits 60 C!
And on "0x46" may be after 65C or 70C!

Main problems:
Why I have two "0x0,0x0"?
I want to make:
A)Windows XP to stay on 20 % (0x14) - till the temperatures hits 50C.

B) After 50 degree to run on 50 %(0x32)!

Security/Secure buffer:

So Can you please help me to do it?

My skype name: "gligsan"
My Email:
Please contact me!

Ali sa...

I'm not familiar with with the DSDT table of 6730s, but it seems like you found the right code.

The temperature that regulates the fan speed is'nt actually a temperature, but a combination of CPU, GPU and internal components. In my case this shows as a thermal zone in HWMonitor.

Moreover, I dont know how to change the temperature intervals that regulates the fan speeds.

Please try to figure out which thermal zone shown in HWMonitor is doing what and send a new comment if you can figure out the problem.

darkwolf sa...

Hello Ali!
Thank you for your attention and for the information!
Before 2 days I found post in with info about thermal zones in HWmonitor!

FDTZ is your fan speed not temperature, so i believe its 50%.

I can hear how the fan turns "OFF" and FDTZ becomes 0 (zero)!
After the Fan turns "ON" it jumps back to 50 C (50 %)

GFXZ = graphics card
DTSZ = digital thermal sensor
CPUZ = cpu temp

TZ = chipset thermal zones

I made archive file for you with HWmonitor picture and my DSDT.ASL table!
You can download it from here:

IF you have some problem with rapidshare, please send me Email at and I will send you back reply with the file!

I have one easy idea.Can I just change 0x32 (50%) to 0x14 (20%) for example!Or may be 50 % to 30%...
Because directly from 0 % to 50 % is big step, and the fan becomes noise!

Thank you Ali!

Ali sa...

well thats the idea. Sound ok, but try 40% or 35%. Good luck!

darkwolf sa...

Hello Ali!
I'm glad to tell you - YOUR PATCH WORKS GREAT MATE!
I will provide you complete tutorial video tomorrow!
But for now:

I decreased to 40 % (speed)as you told me.
I found my Digital thermal sensor zone (DTSZ) is always frozen!When it is frozen on some high temperature - 50-60-70-80 C - the fan works non-stop"!
When I restart/stand by (always)/turn off/on power supply - DTSZ changes its status to lower temperature and the fan becomes to work normal - under 50 C - 0 speed - Fan Off; around 50 C - 50 %; 60 C - 60 %; 70 C - 70% !
I believe I have hardware issue with Digital Thermal Sensor!

"The service specialist in my local point saw and accepted - "with the problem under Windows".But because my fan works under BIOS and under F2 HP Diagnostics Test (outside the Windows) like:
5 minutes totaly FAN Off;after directly 15-30 seconds very loud Maximum Fan Speed;2-3 minutes Fan Off;after directly 15-30 seconds Maximum Fan speed....
So the specialist don't want to help me with someting real.By his opinion because the fan works Off and On under BIOS - the problem is the Windows.

I still have some hope HP will replace my machine or will check my digital thermal sensor!But in Bulgaria (my country) is full with morons!

Now IF I have bad luck with my HP service specialist here - I will just adjust some of (my) speeds to comfortable level!


Ali sa...

Glad to hear that.
However, DTSZ is very slow at updating itself... so it may take some time to reduce DTSZ temp.

sfpeasant sa...

Hi Thanks for the tutorial. (the fan on my dv5z with the athlon x2 ql-60 cpu was driving me insane).

I made the changes to the ASL file as you suggested, but when It's time to load the file, I get an error saying that the registry path does not exist. Do you know what might be wrong? Thanks!

c:\ACPI>asl /loadtable -v dsdt.aml
Microsoft ACPI Source Language Assembler Version 3.0.1NT [Aug 29 2006, 14:17:49]

Copyright (c) 1996,2006 Microsoft Corporation
Compliant with the ACPI 3.0a Specification

DSDT info for update image (dsdt.aml)
Size of image: 38476
OEM id.......: HP
OEM Table id.: 30F2
OEM revision.: f0000000
Error: Count not access the registry path: System\CurrentControlSet\Services\ACP

c:\ACPI> dir
Volume in drive C has no label.
Volume Serial Number is CEB3-BB17

Directory of c:\ACPI

01/29/2009 07:50 AM .
01/29/2009 07:50 AM ..
11/03/2006 12:54 PM 184,168 asl.exe
01/29/2009 08:00 AM 38,476 dsdt.aml
01/29/2009 07:57 AM 287,858 dsdt.ASL
01/29/2009 07:47 AM 38,480 dsdtorig.aml
09/29/2008 10:37 PM 11,264 equus.exe
5 File(s) 560,246 bytes
2 Dir(s) 27,109,937,152 bytes free


sfpeasant sa...

nevermind... the loading works now. I did not follow the instructions and failed to run cmd as an admin. THanks again!

sanndy74us sa...


Would you know how to use DSDT to tweak the BIOS to enable Ultra DMA on the DVD drive?

My nc8430 comes with the TS-L632D drive which is Ultra DMA 2 capable; but HP somehow locks it down to use Multi Word DMA Mode 2.

Clément sa...

I found your blo very interesting for reducing the fan speed of the HP DV series.
I just got a HP Pavilion dv7-1005ef and tried to reduce the fan, quite noicy. I followed your recommendations and all was fine, up to the openin of the dsdt.aml file with the notebook. The results are unreadable... (see below ! Nothing to do with what can be seen on your blog...)
Would you have and idea to solve the problem?
Thanks in advance.



Clément sa...

I did a mistake and read the aml file.. Sorry for the touble.

Myren sa...

I am really glad to se a possible solution to the fan noise problem. I am having trouble creating the file "dsdt.aml" in the C:\ACPI directory. I do as you describe: Enter the subkey path in the EQUUS promt: HKEY_LOCAL_MACHINE\HARDWARE\ACPI\DSDT\HP___

And afterwords the keyname:00000000

the file "dsdt.aml" does not appear in the C:\ACPI directory

I use Vista 64 bit. Do you see any trouble?

Thanks, Thomas

rata de chapinero sa...
Denne kommentaren har blitt fjernet av forfatteren.
Diana sa...

I have an Hp Pavilion dv7. I went through all the steps, but at the end of the step number 14, after typing asl /loadtable dsdt.aml, I get this error in the command window:
Error: Count not access the registry path: System\CurrentControlSet\Services\ACPI\Parameters\DSTDT\HP____\VADER___\00000001
And I also have restarted my computer, but I get the same loud noise.
I would truly appreciate if you can help me.
Thanks in advance, Diana

Ali sa...

To Diana: Sounds like you forgot to run the command line as "Administrator". You're running Vista, right?

Ali sa...

To Myren: If I don't remember wrongly, the code in equus just ignores errors. So make sure you put the correct path. Because the program won't warn you in anyways, it just won't work!
On the other hand, I'm not familiar with x64 systems... Sorry. I hope if you figure it out you will share it with me :) Good luck!

Tose sa...

Hi, I have an hp ze5258 and i cant find nothing for the fans in my DSDT table. Any help?

Ali sa...

Hi Tose,

From what I can see, ze5258 is an older HP model. I know that the DSDT was written in a different manner back in those days. I'm sorry to tell you that the method I describe will only work on more recent generation of notebooks. Cheers.

Seyed Mahdi Hosseini sa...

Hi ali,
thanks for your nice tutorial ,
i have a non-hp model, it is hyundai!,
when i connect to AC power, my notebook fan goes high and cpu temp goes to 85 dg!, also when i surfing web or watching movies, my notebook fan speed up!, even when i just tuch mose it's fan have bad noise!, i use i8kfan tool to monitor my fan and cpu and it is show that cpu loading is very variant,
i dont know how to solve this problem!,
i will try your method and hope it work for me,

mati sa...
Denne kommentaren har blitt fjernet av forfatteren.
mati sa...
Denne kommentaren har blitt fjernet av forfatteren.
mati sa...

Hello! I have HP DV7-1070el and I have a question where are these line that are for FAN speeds? I don't know what to change :( PLEASE HELP!!

This is my dsdt.asl:

Ali sa...

Hi Mati,

I can see that your DSDT differs significantly from what I have seen before. Anyway, would you send me some screendumps of HWmonitor, while your fan is at different speeds?

mati sa...
Denne kommentaren har blitt fjernet av forfatteren.
mati sa...
Denne kommentaren har blitt fjernet av forfatteren.
mati sa...
Denne kommentaren har blitt fjernet av forfatteren.
mati sa...

It's strange, but i don't have fan speeds in HWMonitor, I only have temperature of CPU, GPU, HDD, THRM and this is all. I use 1.13 version. My fan is off, but when GPU temp reaches 59C it turns on, and cools GPU to 45C then turns off. This is happening over and over again... and in idle of course. I have F.25 BIOS and option FAN Always ON: Disabled. Maybe I mus Enable this option to see FAN in dsdt?

mati sa...
This is my dsdt when FAN is always on is: Enabled. I don't know if something changed... I still can't see speeds of my fan in HWMonitor or even Speedfan. My fan is on now and it doesn't turn off.

Ali sa...

The DSDT is static. I can't help you unless you send some pics with different fanspeed.

mati sa...

I know, but the very problem is that I don't have any fan speeds and I don't know why. Maybe you have some idea?

Love sa...

I have the same problem as you Mati. I got a dv4-1090eo and my dsdt file is similar to yours. So if anyone know where to find the fanspeeds, please tell us.

Ali sa...


The fan speed tend to be reported as a temperatur to HWmonitor. I suspect that THRM is your fan speed. Thus, please post the screnndumps.

mati sa...
Denne kommentaren har blitt fjernet av forfatteren.
mati sa...

Ok, so I have screen dumps.

This screen shows temperatures when FAN STARTS (on):

and this screen shows temperatures when FAN STOPS (off):

Ali sa...

Hi Mati,

I looked through your DSDT. It seems like the fan speeds are controlled in a binary manner... just as you told me: its just ON and OFF! I dont think you can change the fan speed... However, keep looking.

vader 2112 sa...


i followed the steps on my 8710w /nc65xx, but after rebot fanny was fanning away at 70%.

Results negative and unchanged

I`m using 64 bit windows 7 beta, and the F.0E bios version. Anybody got some results/solutions on 8710w w. vista / 7 32/64?

vader 2112 sa...

zup again

After rebot the changes i made to the DSDT table is gone...,
it seems like the bios overrides my patching. suggestions?

Ali sa...

That might be a BETA debug feature or something... I use Vista 32-bit.

mati sa...

Thanks Ali, but can I change somehow from what temperature fan is on and off?

nclacuk sa...

The solution provided for reducing fan noise can solve many problems that users have, particular with HP laptops.
In my case I bought an HP Pavilion dv7-1103ea before 1 month.
I am following the procedure described but having found a code with the described characteristics I am actually changing the brightness level of my LCD screen.
My main point is that I can’t identify which is the code related with the control of fan speed.
If someone could help me find the right code I would appreciate it a lot.
By solving my problem with an HP dv7 laptop, users will stop suffering from the annoying fan noise. Thank you for your time. For any further information’s please request them.

Ali sa...

Hei nclacuk.

It seems like the DSDT of the HP consumer notebooks is different from the business notebooks. Its the same problem Mati had. I don't think you can change the fan speed of the latest dv series, because they seem to have only one speed - on and off! And I can't see if it's possible to alter the temperature which triggers the fan. Sorry..

vader 2112 sa...


I am trying to figure out where it goes wrong...I have two questions.

In step 14. does the "asl dsdt.asl" command update the dsdt.aml file my c:/acpi folder?

And if so, am i supposed to se the changes in a new .asl if i type "asl /u dsdt.aml" (By changes I`m referring to mods in step 12 and 13)

Anyways this is a Spanktastic guide. It`s people like you who makes the world advance.

Ali sa...

Hi vader,

In step 14, you compile a machine language version of your dsdt. (dsdt.asl -> dsdt.aml). And then your new dsdt is loaded to the registry. To be able to see the changes, you have to start from scratch... got it?!

mati sa...

Ali one last question, maybe you know how to reduce temp. of GPU?

Grrooom sa...

Thanks anyway Ali, I knew I need a new one :) but no more HP.

Diana sa...

hELLO, now that I'm trying this again, when I generate de file dsdt.aml it appears to be empty (0kb) I don't know why, I appreciate your help.

Ali sa...

Hi Diana,

If you read the posts above you will discover that it is not possible to change the fan speed of the new dv4, dv5, dv7.... series. At least as far as I know.

Diana sa...

Thanks Ali

jonilange sa...


I created the ASL File, but can't find the Fan speed settings! Can somebody help me? Its from an HP dv3550eg.

Thanks a lot!

F03N1X sa...


great instruction!!!!

I have a HP 6730s (FU328ET).

First I removed Vista and installed XP.
(Note: To install XP you have to:
1. diable ACPI in BIOS
2. install XP
3. Go to system manager-> IDE/ATAPI Controller-> update driver-> select source manually->select folder which contains Intel Matrix Storage Manager drivers(> select Intel (R)ICH9M-E/M SATA AHCI Controller
4. restart computer -> switch back to ACPI on BIOS

Do not forget to download all drivers from HP hompage and save it on a different partition than XP installation before installing XP! LAN and WLAN drivers are not within XP installation.)

I followed your instructions.

Path for equus.exe was:
Subkey was:

I opened dsdt.asl wit Notepad++:

I changed 0x32 (50%) to 0x1E (30%):

Name(CPFS, Package(0x6)

Now I can enjoy the silence of my HP 6730s.

To safe battery and minimize temperature I use NHC (Notebook Hardware Control):

To show notebook temperatures I use SpeedFan:

The cpu core temperatures keep between 37 and 42 degree.
The fan is now running with a constant speed with low noise.

Thanks for this great instruction.

Danstan sa...

Hello everybody and Ali especially,
I have 6730s, I did everything as is very clearly described here, but with no success. I think that the problem is in point 14 when I command asl dsdt.asl it writes me the following:
2731: Subtract (SizOf(), DerefOf(Index(BCLS, BCLI,
)), )
dsdt.asl(2731): error: expecting argument type „SuperName“
Then everything goes smoothly and after restart no change.
Thank you for any suggestion.

fenchelteefee sa...

Dear All,

I'm feeling very lucky since I found out that there's a potential method to reduce the intolerable noise, my ears suffering from most of the time.

Unfortunately, by following the step-by-step guide, it wasn't feasible for me to get a "dsdt.ASL" file with desired content.

What I get is a "dsdt.ASL" file without any data. Just a file with 0 KB weight.

Consequentially, at this point, I cannot alter anything with hex-converters, due the fact that the file I got is completely empty (when opening the generated "dsdt.ASL" with the notebook, a blank page appears).

Moreover, when accessing equus.exe, I'm not able to paste the key I copied to clipboard from the registry. I was forced to enter the reg path manually by my own. Confusing to me...

My Specs:

HP Pavilion dv5, Turion X2 2.10Ghz, 2Gb RAM, Vista Home Premium 32 bit(OEM)

My dedicated reg-path (which I cannot paste to the dialogue box, while opening "equus.exe")


Thanks a lot in advance for your valuable considerations on this,

My very best regards from Moscow,


noweezernolife sa...

hi i cant install equus. it runs an error and terminates.

noweezernolife sa...

hey actually i managed to open the dsdt.asl file in notepad but cannot find the fan speeds, there is no list staring with 0x64 but it is all over the place.i have hp pavillion dv6000 and my fan noise is so annoying.if i upload my dsdt file would somebody be able to help me.

Martin Gallant sa...

Your procedure worked great for me on nc8430 Core Duo T2500 Windows 7 Beta 32-bit.

Recommend you disassemble and clean heatsink/fan assemblies, and reassemble with new thermal paste if noise is an issue. A lot of dust cakes in there over time.

Test applied fan speed% by monitoring ACPI TZ5 register.

jeff sa...


Thanks so much for making this guide!
I just tried it on my nc8430 with Windows 7 32bit. (I previously was using NHC with XP).

Does anyone know how to change what temperature the fan speeds are effective at, like what you could do in NHC?

According to NHC, they are 50/60/72/83 deg. C by default. I'd like to change 60 to 65 deg.


All Freakz Base Camp sa...

I'm implementing this article, how it will be work

Buy Hp Notebook and Accessories

Skait Media sa...

I have it worked for hp 6710b with Windows XP sp3 and registry key HKEY_LOCAL_MACHINE \ HARDWARE \ ACPI \ DSDT \ HP____ \ nc75xx. The problem was that the ASL file code does not compile back to AML, even without changes, this post has helped me (see paragraph 10), after adding all the brackets it compiles.

Tamas sa...

Hi, I manage to copy the dsdt file and it's all there. But once I attempt to open in notepad, nothing shows up. Do you know what I might be doing wrong?

Robert S sa...

Thanks for this! I am using a HP dv5, and having difficultis to find the lines responsible for fan speeds.

You mentioned eralier that these laptops amy not have the possibility to change the speed - I would like to mention that this cannot be true, as my fan i running dlower and faster depending on the load (temp). Any idea how to find the right lines?

My best!

seskanda sa...

Ok, i made the dsdt.asl file, but in notepad i can NOT find the fan speeds, there's NO list starting with 0x64, but it's all over the place! My laptop is hp pavillion dv1000.

Download my dsdt.asl here:

Some help would be great.

smulis sa...

To Mati:
maybe you know how to reduce temp. of GPU?

Google/Ebay for "copper shim pad" and when applying use good thermal compound like Arctic Silver Ceramique.

I have done it for HP DV6 series.
There is physical gap between GPU and heatsink (on certain models even 1+mm) and it is filled with kinda silicon type thermopad which not work as it should! Also thats why there are those GPU overheating problems (dead gpu=blank screen) for HPs. For example, your comp is left running for a night- idle CPU with low temp makes Fan turn-off while GPU keeps heating up. In my tests HWMonitor shows that idle CPU is 40-45*C, Fan off, while GPU heats even up to 95*C and still Fan off.

So, i have fixed lots of HP Laptops thermal problem in this way (even resurrected some faulty GPUs). Just carefully clean CPU, GPU, Heatsink surfaces with cotton+spirit (do not scratch) and place a fresh good thermal compound like Arctic Silver Ceramique or Arctic Silver 5 and add that copper shim if needed- ofc applying thermal compound on both sides as well. My experience shows that it drasticly decreases CPU/GPU temp and therefore also Fan works slower. Ouch, and one more thing, if you have accessed heatsink with fan- remove fan cover and take out dust clog which usually blocks normal airflow through heatsink ribs.

Must be advanced in dismantling Laptops/PCs. All works must be done at your own risk and remember that you can damage your computer permanently! Allways disconnect power/battery first!

Jon sa...

You are a genius. Thank you so much for posting this.

For anyone who can't find 0x64 anywhere in the file, you're viewing the dsdt.AML file, which is wrong. You probably missed step 5c to create .ASL file from .AML.

5c: asl /u dsdt.aml

That should be it!

Again, thanks so much. The fan was driving me nuts.

Ronan sa...


This worked great for me. I have a compaq that i was worried about overheating. It gets crazy hot, so i wanted the noisey fan to be on 100% all the time.

I have a evo n610c.

My asl file was a little different to yours. The section related to the fan looked like this:

Name(C1E4, 0x64)
Name(C1E5, 0x46)
Name(C1E6, 0x28)
Name(C1E7, 0x0)
Name(C1E8, 0x1)
Name(C1E9, 0x2)
Name(C1EA, 0x3)
Name(C1EB, 0x0)

i changed it to

Name(C1E4, 0x64)
Name(C1E5, 0x64)
Name(C1E6, 0x64)
Name(C1E7, 0x0)
Name(C1E8, 0x1)
Name(C1E9, 0x2)
Name(C1EA, 0x3)
Name(C1EB, 0x0)

Now the fan stays on maximum all the time and the cpu temperature is down 10 degrees

Thanks for this

Catatan Usang sa...

Hi ...
thank you for your tutorial. but, i have one problem.I cann't find list of numbers that stars with 0x64 and ends with 0x0 in my dsdt.ASL file.
I use HP Compaq CQ41-110AU and installed with Win 7 ultimate.
Some body help me, where's wrong??

You can download my dsdt.ASL file from this link :

IF you have some problem with this link, please send me Email at and I will send you back reply with the file.

Thank you ...

Thαℓℓes ™ sa...

I had a HP DV4 2112br and i cant find the place of zone thermal.
Please analises my .asl

and send me anything for


Anonym sa...


I have a HP DV8000 CTO notebook and in the DSDT file i have two spots that might look to be the fan speeds (both the same and looking like that :

}) )

Here you can find the file

Please advise where to make changes


keith sa...

hi , I have a Hp envy 14. two fans in the laptop and very noisy.
here is the dsdt table.

my system runs on i5 -520 (two cores) / windows 7 home pre 64bit. I couldn't find the fan algorithm. can you help me with finding the part related to fan control.. appreciate your work a lot.

Lacking, In Cheddar sa...

Great guide! equus.exe wouldn't launch for me - gave the error 'application failed to initialize'.

Found an alternate program to extract the DSDT tables here - says it's for 7 only, but it worked fine on XP. Just ignore the patch section, that's intended for Eee PC's I think.

Sailesh sa...

Hi Ali

I have a HP Mini 5102 with BIOS ver F.20, using the latest Sep 2011 iasl I get 2 errors and 4 warnings. :( Please could you help?

Errors are both 'invalid combination of length and min/max flags' whilst warnings are to do with 'reserved methods' 'resourcetag' 'effective AML package length'.

Thank you!

JoNuclear sa...

I have a HP dv7 4180eb with serious noise and heating problems.
Can someone please check my DSDT code and say what to change? Please contact me at or in this forum.
Thank you very much!

JoNuclear sa...
Denne kommentaren har blitt fjernet av forfatteren.
JoNuclear sa...

the only section where i can find 0x64 on the tip is:

Name(BCLT, Package(0xd)

How should i change this?

Czarls sa...

Hi guys! Don't You know where Can I download the app to extract the binary code, extractdsdt or equus.exe? because those files don't exists anymore...maybe You could send it on my @, . Cheers!!

Czarls sa...

Hi Guys! Could You send me please application do extract DSDT table? equus.exe or extractdsdt. because the link doesn't work anymore! Cheers!

Sebastiaan van der Wal sa...

Many thanks for your guide! I had to search a long time before I had the equus programm...

Ikem sa...

I used a Cygwin shell to get the dsdt.dat:

reg query 'HKEY_LOCAL_MACHINE\HARDWARE\ACPI\DSDT' /s /t REG_BINARY|sed 's/.*BINARY.//'|xxd -r -ps>dsdt.dat