CH341A can read bios chip but wont erase

Discussion in 'PC Hardware' started by DontBeThatGuy, Jan 1, 2016.

  1. DontBeThatGuy

    DontBeThatGuy MDL Novice

    Jun 20, 2015
    23
    0
    0
    I am trying to program a SST 25LF040a with my CH341A programmer. I am not having any trouble reading the chip. I took several dumps and all of them are good. But for some reason the chip will not erase. The software says it erased (although seemed extremely fast) but while doing a blank check i am getting "the chips are not null" Also if i try to program with a different dump from another mobo (same model) i get "chip with the contents are in disagreement"

    I am kinda stumped at this point. The only issue i can think of that may be relevant is i could not find my exact chip in the software, theres only a listing for SST 25VF040a where mine is LF. I am not sure that makes a major difference.
    please help.
     
  2. DontBeThatGuy

    DontBeThatGuy MDL Novice

    Jun 20, 2015
    23
    0
    0
    Soldered the chip back on the mobo and its fine so i know its not the chip. I am not sure why the CH341a usb programmer won't erase this chip.
     
  3. LatinMcG

    LatinMcG Bios Borker

    Feb 27, 2011
    5,390
    1,464
    180
    some chips require a special mode .. SST mode to unlock ..
    research your chip model and version of soft for that ch341a
     
  4. DontBeThatGuy

    DontBeThatGuy MDL Novice

    Jun 20, 2015
    23
    0
    0
    I am using 1.17 software that came with the CH341a. I did research the chip and there doesn't seem to be a major difference between my "LF" and the "VF" model that is listed in the drop down menu in the software. The only noticiable difference comparing both datasheets is "Single 2.7v-3.6v read / write operations" (VF) and "Single 3.0v-3.6v read / write operations" (LF)
     
  5. mockingbird

    mockingbird MDL Member

    Mar 13, 2011
    110
    7
    10
    If you're interested in purchasing a license for the latest version of the software, send me a private message, as I am in touch with the author.
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  6. DontBeThatGuy

    DontBeThatGuy MDL Novice

    Jun 20, 2015
    23
    0
    0
    I found a solution thanks to the Flashrom Devs.
     
  7. davidm71

    davidm71 MDL Novice

    Sep 8, 2012
    20
    0
    0
    What was your solution? I had a similar problem and my fix was buying a new bios chip. What was yours?
     
  8. DontBeThatGuy

    DontBeThatGuy MDL Novice

    Jun 20, 2015
    23
    0
    0
    A friend of mine spoke with the Flashrom Devs about adding support for CH341a programmers and compiled a version to use with SystemRescueCd. Support is limited so write speed is slow but it works.
     
  9. ShadowCoder

    ShadowCoder MDL Novice

    Nov 1, 2013
    1
    0
    0
    I had much better luck with the ch341prog tool by setarcos (search for it on GitHub).

    You just need gcc and the libusb development libraries installed to compile with make. Worked great for me when the Chinese software refused to erase/write my chip.
     
  10. DontBeThatGuy

    DontBeThatGuy MDL Novice

    Jun 20, 2015
    23
    0
    0
    #10 DontBeThatGuy, Jan 8, 2016
    Last edited: Jan 8, 2016
    (OP)

    Thanks. Does it work with SST25LF040A ? Also, hows the write speed? Using flashrom it takes roughly 90 minutes.

    Update: that ch341prog doesnt seem to have support for the SST25LF040A chip.
     
  11. Sk4t3

    Sk4t3 MDL Novice

    Jan 20, 2015
    26
    21
    0
    You can test other programmers:

    - TL866A USB Universal Programmer (the best choise for me)
    - EN25T80 USB Programmer (limited use, only for SPI Flash Bios 24CXX25XX)
    - SIVAVA Willem EPROM Programmer PCB50B (another good choise)

    Good Luck!
     
  12. DontBeThatGuy

    DontBeThatGuy MDL Novice

    Jun 20, 2015
    23
    0
    0
    As i said, I already found a solution using my CH341a programmer with Flashrom.
     
  13. hershins7

    hershins7 MDL Novice

    Aug 7, 2016
    1
    0
    0
    Helpmeeee

    Hello, I have the ch341a programmer and I could not fix the problem, as you did?