N4640G bios recovery procedure

plavielle
plavielle Member Posts: 13

Tinkerer

Hi.
 My computer
Acer Veriton VN4640G_W)
SNID : 72500***********
S/N : DTVQ0E*************

After a bios update under windows 10 computer doesnt start (one long beep, one short beep + black screen and fan on)
There is a way to recover bios (create usb boot disk dos + bios file with specific name : i've tried AMIBoot.rom / BIOS.FD / R02-B1_H.FD / RCVBOOT.CAP with no luck)

Thanks for your help

(Thread was edited to add model name to the title)



Best Answer

  • plavielle
    plavielle Member Posts: 13

    Tinkerer

    Answer ✓
    Here you can put this response into topic "how to recover N4640G bios"

    What you need to check before to start is the reference of the bios chip (generally near cr2032 battery) and check it work at 5V or 3.3V. If not you can damage the chip. I think this procedure can work on most computer without desolder the chip. Otherwise you can buy an soic clip (more easy if you dont have soldering skills).

    The material you need is :

    1 - A raspberry pi (i have used a 3b+)
    2 - a raspberry os (i use the latest debian 10 desktop from raspberry site)
    3 - the software "flashrom" (integrated in this raspos)
    4 - chip documentation, all chip have the same pin configuration, but sometimes you have to put pin 7 and 3 to VCC (check on the doc)
    5 - The bios file from vendor (if it have the same size than the chip it's ok / if the size differ you need to have the file bios extracted from a good computer)
    6 - Verify pin configuration of your Raspberry Pi Header (you need 3.3v or 5v, Mosi, Miso, Clk, Cs)


    1 - Dont forget to pull out bios battery and push bios reset button or jumper
    2 - extract 2 time the bios from good computer and compare file (flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=1000 -r good-bios.bin -c "the model of your bios chip")
    3 - program bios on dead computer (flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=1000 -w good-bios.bin -c "the model of your bios chip")
    4 - extract 2 extract 2 time the bios from dead computer and compare file with bios image of good computer (cmp -l good.bin dead.bin or diff *** ***)

    Now the computer works well (some computer needs to reboot more than 2 times to be ok, dont be afraid).

    P.S : An important think was that if you dont have another good computer, you are dead. The image bios on acer site was 8mb or 6mb and the chip was a 16mb (mx25l12873f)?????.





Answers

  • Larryodie
    Larryodie Member Posts: 1,748 Community Aficionado WiFi Icon
    Did you try the basic step  of pulling or replacing the bios battery for an over night session ?
  • plavielle
    plavielle Member Posts: 13

    Tinkerer

    Not for a night. I've pull away for 20 minutes only. I can try this.
    Thanks
  • Larryodie
    Larryodie Member Posts: 1,748 Community Aficionado WiFi Icon
    Also unplug the computer, overnight. 
  • plavielle
    plavielle Member Posts: 13

    Tinkerer

    we're going to view tomorrow. bios battery + unplug. If it doesnt work i'm going to try to dump the bios (16MB chip) and write to this computer (if i dont crash the good one).
  • Larryodie
    Larryodie Member Posts: 1,748 Community Aficionado WiFi Icon
    I think that you need a Bios Programmer to program it.
  • plavielle
    plavielle Member Posts: 13

    Tinkerer

    i think, but the bios fil on acer web site = 6 MB and Bios chip is a 16 MB. Another strange thing. Thanks for your help
  • Larryodie
    Larryodie Member Posts: 1,748 Community Aficionado WiFi Icon
    You may look on EBay for used or used MB. 
    Have you by chance tried ALT -F10 on boot. Doubtable but worth a try or two. 
  • Unknown
    edited April 2022
    This content has been removed.
  • plavielle
    plavielle Member Posts: 13

    Tinkerer

    Answer ✓
    Here you can put this response into topic "how to recover N4640G bios"

    What you need to check before to start is the reference of the bios chip (generally near cr2032 battery) and check it work at 5V or 3.3V. If not you can damage the chip. I think this procedure can work on most computer without desolder the chip. Otherwise you can buy an soic clip (more easy if you dont have soldering skills).

    The material you need is :

    1 - A raspberry pi (i have used a 3b+)
    2 - a raspberry os (i use the latest debian 10 desktop from raspberry site)
    3 - the software "flashrom" (integrated in this raspos)
    4 - chip documentation, all chip have the same pin configuration, but sometimes you have to put pin 7 and 3 to VCC (check on the doc)
    5 - The bios file from vendor (if it have the same size than the chip it's ok / if the size differ you need to have the file bios extracted from a good computer)
    6 - Verify pin configuration of your Raspberry Pi Header (you need 3.3v or 5v, Mosi, Miso, Clk, Cs)


    1 - Dont forget to pull out bios battery and push bios reset button or jumper
    2 - extract 2 time the bios from good computer and compare file (flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=1000 -r good-bios.bin -c "the model of your bios chip")
    3 - program bios on dead computer (flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=1000 -w good-bios.bin -c "the model of your bios chip")
    4 - extract 2 extract 2 time the bios from dead computer and compare file with bios image of good computer (cmp -l good.bin dead.bin or diff *** ***)

    Now the computer works well (some computer needs to reboot more than 2 times to be ok, dont be afraid).

    P.S : An important think was that if you dont have another good computer, you are dead. The image bios on acer site was 8mb or 6mb and the chip was a 16mb (mx25l12873f)?????.





  • Larryodie
    Larryodie Member Posts: 1,748 Community Aficionado WiFi Icon
    Are you saying that this worked for you ?
  • StevenGen
    StevenGen ACE Posts: 12,508 Trailblazer
    plavielle said:
    we're going to view tomorrow. bios battery + unplug. If it doesnt work i'm going to try to dump the bios (16MB chip) and write to this computer (if i dont crash the good one).

    Hey plavielle the easiest way is to replace the bios chip with a new one (they are much cheaper than getting all these flashing bios complicated tools that need expertise to use) you can contact a renowned bios chip distributor or retailer as there are plenty of bios chips for sale on the web for the Acer Veriton and I’m sure that they have one for the N4640G bios chip, which all these bios chips also come flashed with the last bios version, yes it’s a specialist job that need specialist tools but if you get a proper mini soldering iron you can do this job yourself, if not take it to any experienced tech as he should be able to fix this bios problem for you. .


  • plavielle
    plavielle Member Posts: 13

    Tinkerer

    StevenGen, i dont have enought time to search and find some chip or chip vendors, so i have made it. The problem with desoldering is, if you dont have the right tool (hot air gun) you risk to damage the board. I fortunately i have 16 unit of this type so it's easy to get a good bios image.
  • Larryodie
    Larryodie Member Posts: 1,748 Community Aficionado WiFi Icon
    Chip Quick will do the removal but study You Tube Video's before doing so also you can by with a cheap hot air gun not the hot air stations that I have but again, study videos.

    BUT I think that you're on the right track as you have spares to copy the data and transfer.

  • plavielle
    plavielle Member Posts: 13

    Tinkerer

    It's done, i've do it 2 days ago.