Question about Dell Latitude C640 Notebook

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Laptop keeps shutting down, both fans not working

Hello, I have a Dell Latitude C640 that has worked perfectly for a very long time. But all of a sudden one day when I turned it on it kept shutting off after just a few seconds. If I try to turn it on with only the AC adapter connected (no battery) it usually requires that I push the start button a few times before it will turn on, but then it will shut down after a few seconds. If I try to turn it on with just the battery connected (no AC adapter) it will turn on the first time I push the start button, but then it shuts down after a few seconds. After a few times of trying either of these methods to start the laptop it won't start at all and I will need to wait a while before trying again. Regardless of which way I get it to start, I notice that both the CPU fan and case fan are not spinning at all. What would be common to both the CPU fan and the case fan not spinning at all? Is it possible the laptop is overheating in just a few seconds, and this is what is causing it to shut down?
Thank you!

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  • nerdneedafix May 25, 2008

    No it is not under warranty. So I have nothing to lose by opening it up and trying to fix it myself. What does uP mean?

    Thank you for such a quick reply.

  • nerdneedafix May 25, 2008

    If the microprocessor was bad I don't think it would boot into windows at all, even for a short time. No?

    I have done a lot of repair work on desktops, but have never taken a laptop apart. Dell has instructions and schematics on its web site for disassembly of the Latitude C640. I have nothing to lose and maybe I'll get lucky and find something I can fix; like a broken solder joint or something.

  • dan-0-soar Jun 06, 2008

    I have the same problem. I have not yet opened the case but note that the bottom case fan is not spinning. Is there something that I can do? Does this have anything to do with the CMOS battery? Bad connection? What?




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Sounds like you have a bad motherboard, or this under warranty, by chance?

Posted on May 25, 2008

  • Patrick Michaels
    Patrick Michaels May 25, 2008


    you ever done this before? It takes me almost 45 minutes to do this, and that's with 20 years of's like major surgery

  • Patrick Michaels
    Patrick Michaels May 25, 2008

    well..uP can get hot, and slow's not a failure positive device, unless it's hit by lightning.

    i work on Dells all the time..component troubleshooting is problematic, for a variety of reasons



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