Latitude E6400 - Undocking/Docking hibernate/wake problems - General Hardware - Laptop - Dell Community

Latitude E6400 - Undocking/Docking hibernate/wake problems


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Latitude E6400 - Undocking/Docking hibernate/wake problems

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I have been having hot or miss luck with undocking my laptop.  I'm looking first for official instructions on how to undock.

This is how I do it:

  • Fn-F1 to hibernate 
  • Undock
  • press On/Off button on laptop to wake up

Sometimes this works.  Other times, the laptop won't wake up.  And sometimes pressing the On/Off button causes the laptop to shut down.

If I don't hibernate first, the laptop usually locks up and I have to force a hard reboot.

Redocking has the same problems, although it's less likely to lock up.  I don't hibernate when redocking, as I've not found that to make a difference.


What is the proper procedure for undocking?

What is the proper procedure for waking?


(running Windows XP Pro/ Enterprise)

All Replies
  • I get exactly the same problem when undocking or docking it back... Only hard reboot make the laptop back for work with the current work lost if not saved before...

    The problem seems to appears only when it last for a while closed...


    By make it hibernating or even sleep for un/dock is borring.

    I even tried to install the latest BIOS & drivers...

    I just get a freezed windows screen instead of a black screen. Nice is-it?


    Does any one has a workaround to this nightmare ?

  • I support roughly 200 E6400 laptops where I work and you need to call dell support to have your system repaired as it is a design flaw with the laptop and port replicator. Dell will only repair it if you report it as it has to do with a static issue. They will replace the heatsink and fan in your laptop as Dell says that is what is cauing your laptop to lockup when you undock than redock it. Since I ahve ahd that repair performd on my laptop, the problem has disappeared. In the meantime, ground yourself on the metal pins on the dock before docking your laptop to discharge any built up static before docking your laptop as a work around. You should be able to undock normally without putting your laptop into hibernat if you do so.

  • Are you positive on this?  We have about 20 of these laptops in my work envrionment all with Vista OS on it except 3 which have Windows 7.  The Vista one's freeze every time, but all of the Windows 7 machines are hot swappable and do not freeze when undocking or re-docking.

  • FWIW: Lack of the undock option is in direct contradiction to most sane computer system disciplines ... you NEVER disconnect a peripheral device without informing the OS that it's going to be disconnected.

    Failure to do so will probably result in damaged data and ... in some cases ... damaged hardware.

    When you press the undock button (not the eject button) on a Latitude D630's docking station, the hardware sends the OS a signal telling it that you are about to undock the machine.  The OS then tries to disconnect all devices that are attached through the docking station.  If it can't disconnect the hardware (possibly because it's in use), the OS informs you that the undock is not possible.

    Ejecting the computer without going through the undock procedure is equivalent to pulling the plug on the external devices ... if they are in the middle of a disk write, your data will be damaged.

    Microsoft has a tech note on the subject:

    Removing a portable computer without using Undock can result in system instability, data loss, or even hardware damage. To avoid loss or damage, use Undock to undock your computer, or shut down the system and undock the portable computer while your system is off. Undocking a portable computer while it is in either standby mode or hibernate mode can result in data loss and system instability.

    I'm REALLY surprised this hasn't been fixed yet.

  • I completely agree with you.  Why is there no "undock" feature?  Even on my Windows 7 machine that's a Dell Latitude E6420...still no "undock" feature...

  • Here it is a year and a half later and this is still an issue. I use a Dell E6420 at work, and the "only" thing that happens when I undock is my browsers become useless. No matter what tabs I have open, no matter which browser it is (IE, Chrome or FF), no matter what process I follow to undock, the browsers are hosed after I dock or undock. The browsers resize and respond to mouse controls, but none of the browser tabs contain the content the URL suggests they would have. The only recourse I have is to shut down the browsers and restart them (and sometimes I have to do that through Task Manager). Not a very useful "feature" when I'm preparing for a meeting and bring up web pages I intend to refer to during presentation, only to have them not work when I undock to go to the conference room!

  • The safest way I've found is to select Sleep from the powerdown menu.  Wait for the hard drive to finish saving its data.  Once the laptop is in a power save mode (blinking power lights on the laptop and on the dock), it will be safe to push the eject button on the dock). 

    It's possible these models are only partially APCI compliant, and the undock feature is not one that is working.


    Also found this:

  • I have been investigating this issue for a few weeks now and in case it helps - Dell responded last night with the answer that hot docking / undocking is only available in Windows XP.  Since Windows 7 was released in 2009 this may account for a large portion of issues in here...  Still working on it though as another likely scenario is that the docking stations don't support hot docking.....