Dm520hd nand.

Discussion in 'Hardware troubles and Repair support.' started by nicnec, Oct 15, 2021.

  1. nicnec

    nicnec New Member

    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    Hello! I have a Dm525 hd Combo where I think nand flash died and I want to replace it with another one. Does anyone have nand content? Can nand be replaced by another company?
     
  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,547
    Likes Received:
    1,316
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    Untested, but the Toshiba TC58NVG2D4 or maybe the TC58NVG2S3ETA00 seems to me a working replacements.
    More brands can be found here, see the overview of the NAND FLASH – SLC and see there the row with A5U4GA31ATS-BC
     
    raza05 likes this.
  3. nicnec

    nicnec New Member

    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    I replaced nand with a similar one but I still can't install a new image. Are there any commands to test nand with putty? Ex. Full erase ... ! I'll be back with a log.
    Thanks
     
  4. nicnec

    nicnec New Member

    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    I came back with information. At the update from the PC it loads and at the extract it restarts. The online update gives an error.
     

    Attached Files:

  5. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,547
    Likes Received:
    1,316
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    It looks to me as if there is still a issue with the nand flash chip, maybe one bad connection between the chip, and the cpu as the eight I/O pins.
    These could often be measured by ohm, all should have a same ohms reading in the same range when you measure it between a ground spot ant a I/O pin.

    Other option is to download the suitable rescue file from the DMM site and to place it in your tmp dir if you still can reach the box with putty/telnet.
    Then run flash-rescue filename.

    Another idea could be to take a look into this old topic, which may give you some ideas that may help you.

    Or, see if you can find/get a terminal output from someone else, which is related to the online rescue to compare it with yours.
    As the nand flash writing part may say something.
     
    raza05 likes this.
  6. nicnec

    nicnec New Member

    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    I can't find the content in the flash maybe it would solve something. Don't have any flash read and saved?
     
  7. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,547
    Likes Received:
    1,316
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    Yeah I already assumed that yo new nand flash chip must be prepared before doing anything else.
    I also think that the online rescue looks at data on the chip before it will install it.
    I think, see if you can create a tmp directory on the chip with telnet, and upload the rescue file to it and execute it with telnet.

    However it sounds simple, but it never does.
     
    raza05 likes this.
  8. nicnec

    nicnec New Member

    Messages:
    5
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    Does anyone have pinout jtag for dm525 hd combo?
     
  9. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,547
    Likes Received:
    1,316
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    As for jtag, that is useless as all dream boxes are accessible for uploading the software via usb/mini usb service port and network.
    And all dreamboxes can be prepared when it has new blank flash chip, only with vu+ box, it needs to be prepared by jtag, at least the old one.
    If these stop working, there is a serious hardware problem.

    I have checked your log file with one of mine and I see no reasons why it failed with the rescue,
    The only things I can think of is that you must find a way to access the nand chip with telnet, maybe telnet serial mode in bolt mode.

    This can be reached in the serial terminal Bps 9600, and by pressing the CTRL/C buttons and turning on the box so you can get into BOLT mode which gives you the possibility to flash the rescue-dm520.bin file via usb with the following command.

    BOLT> show devices
    BOLT> dir usbdisk0
    BOLT> boot usbdisk0:/rescue-dm520.bin
    Notes that the rescue-dm520.bin file must be present on the usb stick.

    More about it, but from a dm900hd you can read here, but i think that the basics are the same for the dm520/525.
     
    Aliraza63 likes this.