A8n-vm csm/nbp

Discussion in 'BIOS Mods' started by b166er, Aug 27, 2010.

  1. b166er

    b166er MDL Junior Member

    Sep 9, 2009
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    #1 b166er, Aug 27, 2010
    Last edited: Aug 28, 2010
    A8n-vm csm/nbp CMOS Checkum Bad

    Hi,

    Searched the forums and found nothing, not even for A8N.
    I have modded the original BIOS for this board (0114). However, when I try to boot the Windows 7 installer, either from USB or DVD, after POST, I just get a flashing cursor, top left, second character down and the leftmost column is full of capital H's from top to bottom!!!! Never gets any further.
    There is a Beta BIOS for the board on the ASUS site (0119), so I modded this. The 0119 version will boot from either USB or DVD and I am able to install Windows 7. However, EVERY time the computer POSTs, I get CMOS Checksum Bad F1 or F2. No matter what I do (including CLRCLK and removing the battery) I can't get that checksum error to clear.
    I performed the above using AFUDOS2.38 (and AFUDOS2.21) and I also tried using the ASUS Update Utility from within Windows 7.

    The problem is exactly the same with both the unmodded BIOS files too.

    Any ideas, A) Why there is a column of H's using the 0114 BIOS when trying to boot Windows 7 and, more importantly, B) how can I clear the CMOS Checksum error?
     
  2. b166er

    b166er MDL Junior Member

    Sep 9, 2009
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    I just tried flashing the latest BIOS for A8n-vm csm, which is identical apart from the GeForce 6150 (the A8n-vm csm/nbp has the 6150b).
    AFUDOS complained about ROMID not matching.
    Will it kill the board if I manage to flash this ROM onto it?
    Can I change the ROMID to match somehow?
    Could the 6150B code be inserted into the ROM for the 6150?

    Desperately trying to save this board from the scrapheap.
     
  3. NoJuan999

    NoJuan999 Experienced SLIC Tool Operator

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  4. b166er

    b166er MDL Junior Member

    Sep 9, 2009
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    Can someone confirm whether I can fix the checksum or not, please? :)
     
  5. Yen

    Yen Admin
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    May 6, 2007
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    It seems that the setup defaults when loaded into non volatile memory (at boot) causes a wrong sum there.....every time....
    Either the bios is faulty (Asus did it wrong), or some parts are not updated at flash process....

    To exclude the latter flash it like:

    Afudos /ixxxx.rom /pbnc /n

    xxxx.rom is your original bios.

    Or a sum of a decompressed module is not right...
     
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  6. b166er

    b166er MDL Junior Member

    Sep 9, 2009
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    Thanks Yen, and sorry for the duplicate post. This one had too specific a title and didn't attract enough gurus such as yourself and NoJuan999!
    I tried flashing the BIOS using the command line switches you refer to, but the versions of AFUDOS I used, didn't like them. I will try again and report back.
    I installed Ubuntu 10.04 and GRUB to the MBR, chainloading the Windows bootloader, but still no dice. Still get all the H's and the system locks up.

    In the original 0114 BIOS, there is a section for Trusted Computing, with an option to turn this on or off.
    In the 0119 BETA BIOS, the section Trusted Computing is there, but no option.

    If ASUS have made a broken BIOS available, is there a way to fix it?

    Thanks again, Yen, I really appreciate you taking a look :)
     
  7. NoJuan999

    NoJuan999 Experienced SLIC Tool Operator

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    #9 NoJuan999, Sep 9, 2010
    Last edited: Sep 9, 2010
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  8. b166er

    b166er MDL Junior Member

    Sep 9, 2009
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    Thanks for the advice NoJuan999.
    I used the version you suggested (2.36); it accepted to switches Yen advised to use.
    I still have the same problem; 'CMOS Checksum Bad' must press F2 to load defaults every boot.

    Any suggestions what to try next fellas?
     
  9. NoJuan999

    NoJuan999 Experienced SLIC Tool Operator

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  10. b166er

    b166er MDL Junior Member

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    Thanks, I tried that one, still the same :(
    What have ASUS done to it?
     
  11. b166er

    b166er MDL Junior Member

    Sep 9, 2009
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    Yen, any ideas how I can check which module has a bad checksum?