BEFORE you put the Chromebook into developer mode, the Read/Write screw AND sticker must be removed from the motherboard. See pictures below.

Remove the Metal Plate from the Motherboard to get to the screw location in yellow.

Remove the Sticker from the screw hole.

Place the metal plate back on the motherboard and screw in the middle 2 holes to secure it, it is the heat shield for the motherboard so we do not want to leave it uncovered when the device is on. But we must make sure the metal shield does not touch the screw hole or you might get a read/write error, so place a folded piece of paper in between the metal pate and the motherboard until you are done reprogramming the serial number.

Get to developer mode: Toshiba Chromebook CB30-B3121

On this device, both the recovery button and the dev-switch have been virtualized. Our partners don't really like physical switches - they cost money, take up space on the motherboard, and require holes in the case.

To invoke Recovery mode:

• • Plug the DC Power in

• • Hold down the Esc + Refresh + Power until the display turns on then release.

  • At the screen that says the “Chrome OS is missing or damaged”, press Ctrl + D then Enter.

  • At the screen that says “Chrome OS verification is turned off”, press Ctrl + D, the device will restart and progress into developer mode.

  • Do not touch or do anything for 10-15 minutes until it progresses back to the “Chrome OS verification is turned off” screen, then press Ctrl + D

  • Wait until the device boots to the Chrome start screen, Press Ctrl + Alt + → (Ctrl-Alt-F2)

Once in the command prompt continue to the next page, if not in a command prompt retry the above steps.

Once in developer mode: Toshiba Chromebook CB30-B3121

Type as shown below, if it’s Capital leave it Capital, if its lowercase leave it lowercase. Spaces are important make sure if there is a space you type it in the terminal.

• • Type: chronos

    • Press Enter

  • Type: sudo su

    • Space after “sudo”.

    • Press Enter

  • Type: vpd -l (lowercase L)

    • Space after “vpd”.

    • Once you type vpd -l, this will display the current motherboards information including the motherboards current serial number.

    • Press Enter

  • Type: vpd -s “serial_number”=”0000000000”

    • Replace the 000’s with the Device Serial number from the original device.

    • Space after “vpd”, Space after “-s”.

    • Make sure the serial number is CAPITAL letters.

    • Press Enter

  • Type: dump_vpd_log --force

    • Space after “dump_vpd_log”.

    • Press Enter

  • Type: dump_vpd_log --full --stdout

    • Space after “dump_vpd_log”, Space after “--full”.

    • Press Enter

  • To close the command line session, type EXIT to close shell and EXIT to close the terminal.

  • Leave the device in developer mode once the repair is completed, so that the QC Team can Verify the SN Change.