Dell C640 Latitude

By bny800
Jul 6, 2006
  1. my computer says:

    "This computer system, #BYZBWOJ-595B, is protected by a password authentication system. You cannot access the data on this computer without the correct password.

    Please type in the primary or administrator password and press <Enter> "

    someone who can help me,or can give a master password or link to site?

    I have tried much, backdoor passwords memory-sure, Latitude_MasterPW.exe, looked at on this forum,tried, but nothing has helped me. Are able me perhaps with something help you something that works.

    ps: Dell c640 Latitude
  2. Dinram

    Dinram TS Rookie

    same problem is there any solutions
  3. think_guru

    think_guru TS Rookie

    This method seems to work on the c640, and, best of all, it is free:

    I've tried it on an old Inspiron at least. It took me the better part of the day, but I finally got it working! Also very helpful in taking apart the laptop are the Dell service manuals, which can be found on the Dell support website.

    For more information, see the following threads:

    Happy shorting!
  4. Dinram

    Dinram TS Rookie

    can anyone help me to trace the Eeprom chip (24c02 ) on dell latitude C640 and exactly wich pin to short. Coz i tried but seems not working thinking maybe i was working on a wrong chip.
  5. think_guru

    think_guru TS Rookie

    When I was attempting this on an old Pentium 3 Inspiron 4100, the chip wasn't exactly labeled 24C02, however it had "24" and "C02" in the 2nd row. There should be only one chip like this. For me, I had to short pins 3 & 6, but I have seen people suggest different pins as well. I would recommend 3 & 6 as a good starting point, however.

    The pins are numbered counter clockwise starting from the bottom left corner of the chip. You can tell which side is the "bottom" because, when looking at the chip in the correct orientation, the little semicircular cutout should appear on the left hand side.

    Remember, the timing is crucial as well. Once again, I have seen suggestions posted WRT timing. For me, I simply had to apply the short, turn on the computer, and then release it in order to get to the manufacturing mode. However, other people say you need to wait several seconds before applying. Just remember, it CAN be done. You just need to try these different techniques iteratively, or, better still, find someone who has done the deed for your specific model

    Here is a superb guide with some pictures that may prove more useful:

    best regards & good luck!
  6. Dinram

    Dinram TS Rookie

    HI guru me again is number 6 under the little semicircular cutout is it like this



    0 assuming little semicircular cutout
  7. think_guru

    think_guru TS Rookie

  8. think_guru

    think_guru TS Rookie

    Sorry, tried to get a little fancy and it came out wrong .... i forgot that html mucks with the spacing :chef:

    Here it is:

  9. Dinram

    Dinram TS Rookie

    no bro i tried everything i think it won't work on the dell latitude C640
    Can it unlocked by mastercode?
  10. Dinram

    Dinram TS Rookie

    i heard that the problem is the -595B series
  11. think_guru

    think_guru TS Rookie

    Hmm it should work. At least Paragon's website says it will work for that model. If you're still having trouble, you can try contacting Dell. Just give them that service tag, and they should be able to provide you with the master password.

    Also, check out the main thread for password help and leave a post:
    (note this thread will close soon, since it is only for april to July. Once a new one opens, you can check that one out too)

    If you describe precisely what you've done and your shorting technique, perhaps somebody there can give you more information specific to your system.

    Good luck!
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