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Toshiba Satellite P55-A5104SL - corrupted BIOS

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    Toshiba Satellite P55-A5104SL - corrupted BIOS

    Hello all

    Model - Satellite P55-A5104SL
    Mainboard - VGSG MB Ver:2.1
    All flashing done w/CH341 adapter & EEPROM chips off board.

    PROBLEM:

    After updating from BIOS 1.70 to 1.90, it shows Toshiba logo and halts. I narrowed it down to a possibly corrupted BIOS. How do I know? There is no similar machine in the forums, so I tried a dump for another model with same mainboard (L50-A-19N) provided by @ala_borbe in this thread. Flashed this on both BIOS & ME_FW chips and the laptop came to life again! BUT, with these symptoms:

    - Dedicated GT740M GPU no longer works (error code 12 in Dev.Manager)
    - Keyboard no longer works in BIOS, external USB keyboard does
    - Dev.Manager shows "something USB" getting plugged-unplugged forever

    It's clear the L50 files are different enough to the P55 to make them incompatible, even being the same board. I flashed both previously back-upped dumps, and it reverted back to non-booting state. Flashed L50 ones again, boots 'fine' again. So I was positive the original BIOS and/or ME_FW were bad and I just needed the correct ones.

    WHAT I DID:

    All BIOS packages from Toshiba for this P55 contain a 4.198.400 bytes file - 4Kb bigger than chip's capacity. I went with latest 1.90 one. Fiddling around I noted the 1st 4Kb is just a header, so I removed that with HxD Editor and sure enough, the new file looks 'good': 1st KB or so identical to @ala_borbe dump, and it's exactly 4.194.304 bytes.

    Flashed this BIOS, and the same happens: only logo & no boot.
    Did the same procedure to 1.60 & 1.70 original BIOS, same result.
    Tried both L50 & backup ME_FW dumps with 1.60/1.70/1.90 P55 BIOS, no change.
    Flashed back the L50 BIOS+ME_FW, as expected it boots 'fine' (non-working GT740M etc).

    At this point I was scratching my head badly... what to do now ... Then I tried flashing the P55 backup ME_FW mantaining the L50 BIOS, to see if the original dump was bad. It still boots! The original ME_FW dump is good then, it has nothing to do with the problem. The d*mn board simply does not like its own model BIOS. What gives??

    I cannot see any reason why is this happening, but that's where I am now. Also I find suspicious how many people had similar problems with these family of VGSG boards... almost like there's a bug somewhere in the update process...

    WHAT I NEED:

    A matching, working set of BIOS+ME_FW dump for this model the L50 ones get the laptop to Windows, but they're not 100% compatible. ANY version is fine.

    Thank you.
    Last edited by sndestroy; 05-09-2021, 12:22 AM.

    #2
    Re: Toshiba Satellite P55-A5104SL - corrupted BIOS

    post the backup of the bios, just as corrupt.
    Due to a lack of donations, server free space at a critical level, and possible closure of Bios Requests all donations are welcome, click:

    >>>>> https://www.badcaps.net/index.php?pageid=donate1 <<<<<

    Every donation made will go towards server fees and maintenance costs.

    Comment


      #3
      Re: Toshiba Satellite P55-A5104SL - corrupted BIOS

      Here you go.
      Attached Files

      Comment


        #4
        Re: Toshiba Satellite P55-A5104SL - corrupted BIOS

        Originally posted by sndestroy View Post
        Here you go.
        try..
        bios extracted from the site update ..
        DMI 4A6B0-4A7CF
        Attached Files
        Due to a lack of donations, server free space at a critical level, and possible closure of Bios Requests all donations are welcome, click:

        >>>>> https://www.badcaps.net/index.php?pageid=donate1 <<<<<

        Every donation made will go towards server fees and maintenance costs.

        Comment


          #5
          Re: Toshiba Satellite P55-A5104SL - corrupted BIOS

          Originally posted by peste View Post
          try..
          bios extracted from the site update ..
          DMI 4A6B0-4A7CF
          Thank you.

          With this dump, Power on -> fan spins, internal display dead (no BL no image), external HDMI goes from "no signal" to a black screen. Does not boot.

          Reset button doesn't help. RAM is confirmed good, same with CMOS battery.

          Comment

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