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Friday, July 25, 2014

Chromebook Tip: How to find the serial number

With our recent shipment and enrollment process of 2,500 Dell Chromebooks we ran into a few instances where the serial number on the device stickers was wrong. I believe something was replaced on the motherboard and the sticker wasn't switched to the new serial number. This caused confusion when I looked in the console and saw serial numbers that weren't in our scanned spreadsheet (we scanned the serial numbers as part of our process) and there were serial numbers in our scanned spreadsheet that I couldn't find in the console!

You'd be able to turn on user tracking in the console and see the last syncs and stuff to figure out which serial numbers matched up but there is also a way to get the serial number by putting it in dev mode.

First move to developer mode (basically the first half of the wipe instructions) and then follow these steps:
  1. On any OOBE screen once in dev mode, access VT2 by hitting 'ctrl+alt+right arrow' [the key above the number 3, or F2 on non-CrOS keyboards]
  2. When it asks for localhost login type root then hit enter
  3. Next, type vpd -l then hit enter
  4. Multiple things will output, but the one you care about is "serial_number" (not "mlb_serial_number" or any other SN reference)
  5. To get out of VT2 and back to the normal OOBE UI, hit ctrl+alt+left arrow (F1)

This works on Dell 11 Chromebooks. I haven't tried other models. But pretty cool!

8 comments:

  1. This comment has been removed by the author.

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  2. We have a Dell CB11 that does not show up in our management console, so it sounds like what you found with yours. The problem is that we cannot enter dev mode until it's de-provision, and you cannot de-provision without knowing the proper serial number. Is there no way to find the serial number without entering dev mode?

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  3. I thought you had to deprovision too -- but you don't. Just esc+refresh+power, ctrl-d to start dev mode, then do the instructions above before logging in for the first time.... Just be sure to stay in dev mode rather than restoring boot verification.

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  4. As far as I can tell, the serial number should have been burned in to match the case if the mb was replaced. The factory process, as far as i can tell, includes setting the serial number. There's even hacks to put a "valid" serial number into Chromium on non Chromebooks, and it should be possible to rewrite it if you go to all the work of opening the case, disabling firmware write protect, void any warranties, and rewrite the system firmware blocks.

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  5. Note that since version 40 the serial number is shown during OOBE at the upper right corner of the screen. Thus all that is needed to access the serial number is powerwashing the device. (details here: https://code.google.com/p/chromium/issues/detail?id=216422)

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  6. Forgot one thing: It might be necessary to press Alt+V or Ctrl+Alt+V to display the serial.

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  7. If you wipe the device, let it finish and go to the screen you get after you remove the usb stick it recovered from, press Alt V and it will display the device serial number at the top right of the screen.

    I just had a device show up on my desk that was deprovisioned and having a time error when being enterprise enrolled. I got it working but couldn't find it in our system. It turns out he had replaced the motherboard using the motherboard from another broken Chromebook and the device on my desk was back in our system as the other broken device.

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