IBM ThinkPad Laptop CPI Fan Does Not Turn on After Computer Switches from Passive Mode to Active Mode

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Article ID: 271717 - View products that this article applies to.
This article was previously published under Q271717
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When your IBM ThinkPad laptop computer is using battery power (Passive mode) and the temperature of the computer is sufficiently high to trip one of the _ACx trip points, fans that are defined in the _ALx may not be turned on. This behavior is designed to conserve battery power. However, the fan may stay off even after you plug your computer into an AC power supply (Active mode).


This problem can occur if Windows does not properly start the fan or fans even though the computer is in Active mode.


To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
260910 How to Obtain the Latest Windows 2000 Service Pack
WARNING: When you restart your computer after you apply this hotfix, your computer may stop responding (hang). To prevent this problem, run the hotfix with the /z switch, and then shut down the computer normally. For example, the command would appear like this:
q271717_w2k_sp2_x86_en.exe /z
The English version of this fix should have the following file attributes or later:
   Date        Time    Version        Size       File name
   08/18/00    4:17PM  5.0.2195.2103  1,678,464  Ntkrnlmp.exe
   08/18/00    4:18PM  5.0.2195.2103  1,678,464  Ntkrnlpa.exe
   08/18/00    4:17PM  5.0.2195.2103  1,699,008  Ntkrpamp.exe
   08/18/00    4:18PM  5.0.2195.2103  1,656,384  Ntoskrnl.exe


Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 2.


For additional information about how to install Windows 2000 and Windows 2000 hotfixes at the same time, click the article number below to view the article in the Microsoft Knowledge Base:
249149 Installing Microsoft Windows 2000 and Windows 2000 Hotfixes


Article ID: 271717 - Last Review: February 20, 2007 - Revision: 3.3
  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional Edition
kbhotfixserver kbqfe kbbug kbenv kbfix kbhardware KB271717

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