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Access denied on Dell Latitude 7490

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jeannets Posted messages 28402 Registration date   Status Contributor Last intervention   Ambassadeur -  
 eloise -

Hello,

I have a Dell Latitude 7490 laptop, and I'm unable to access the BIOS; the screen remains black, and the keyboard backlight works... the battery is charged, and it is plugged in.

It's about 5 years old and running Windows 10.

It won't start, which is why I'm trying to boot from USB in Win PE_SE, but I can't get it to launch... The error indicators are flashing (2 orange and 5 white), which might indicate a "memory not compatible" issue... There was a blue screen yesterday.

Also note that the Caps Lock key remains lit no matter what we do.

The F2 or F12 keys at startup have no effect...

Thank you in advance for your help...

4 answers

  1.
    cathyqiu Posted messages 125 Registration date   Status Member Last intervention  
     

    Hello,

    Is there a problem with the computer's motherboard?

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  2. jeannets Posted messages 28402 Registration date   Status Contributor Last intervention   Ambassadeur 6 603
     

    I can’t know it..? nothing is starting..

    In principle no, but it can come suddenly..

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  3. jeannets Posted messages 28402 Registration date   Status Contributor Last intervention   Ambassadeur 6 603
     

    Here the issue is resolved, the PC is working again, so I'm ending my request...

    For your information, I can't explain what the problem was. Here’s what I did.

    -- I unscrewed the back cover... unplugged and removed the battery... removed the 8GB RAM stick and the 512GB NVMe SSD (Hitachi).

    -- Measured the CMOS battery (OK, 3.15 volts) and checked for anything strange..!

    -- Replaced the battery... and started the PC... nothing happened.

    -- Replaced the RAM stick... and started the PC... accessed the BIOS, it works... updated the date and time...OK... the Dell logo appears, that's OK, with a setup message for the missing SSD and Windows booting...

    -- Reinstalled the NVMe SSD... and started the PC... It boots, starts, and launches Windows without a hitch... everything is fine... the files are present...

    Mystery...!!! It seems that this operation was beneficial and resurrecting for it...?

    I'm providing these details for those who might experience the same issue; just in case.. and I took the opportunity to make a backup...

    There you go, thanks to those who encouraged me...

    A+++

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  4. eloise
     

    Hi

    -it could be a "memory issue (we can always do a RAM test)

    -removed the 8GB RAM stick (or moved in its slot?)

    Then if we look at the troubleshooting procedures for rebooting due to an issue (temporary battery or serious but it restarts the thing), although the tutorial doesn't seem to be designed for exactly the same model), it really looks like what you did.

    https://www.dell.com/support/kbdoc/en-us/000131044/diagnostic-and-battery-indicators-for-dell-latitude-laptops-and-tablets

    It's very hot here.

    -couldn't the laptop have been left in the sun?

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