C720 has damaged ChromeOS, can't install fresh OS

Hi all, I have a C720 Chromebook that doesn't boot up at all, except in recovery mode. It says its operating system is damaged or missing. So I've tried (on multiple flash drives, on many occasions) installing a fresh OS through the Chromebook Recovery Utility. When I plug the flash drive into the C720, it restarts, tries to verify the operating system on the flash drive, and then says "an unexpected error has occurred." The installation process stops right there. I've checked out the error message (https://support.google.com/chromebook/answer/1080595) but haven't found anything helpful over there. Any ideas about what can be done to rescue this machine?

Thanks,
David

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Jack22

Ways to Reset Chrome Book

Option 1: Reset using shortcut keys

1) Sign out of your Chrome book.

2) Press and hold Ctrl + Alt + Shift + R.

3) Click Restart to restart your Chrome book.

4) In the box that appears, click Reset and sign in with your Google Account.

Option 2: Reset using the Settings menu

1) Sign in to your Chrome book.

2) Click the status area, where your account picture appears.

3) Click Settings > Show advanced settings.

4) In the "Power wash" section, click Power wash.

5) In the box that appears, click Restart and sign in with your Google Account.
Note: The account you sign in with after you reset your Chrome book.

Option 3: Reset using the Google chrome

1) Click the menu on the bottom right of the screen. Then tap Settings.

2) Scroll down and tap Show Advanced Settings.

3) Scroll down and tap Power wash.

4) In the "Power wash" section, click Power wash.

5) In the box that appears, click Restart and sign in with your Google Account.
Note: The account you sign in with after you reset your Chrome book.

Option 4: Reset using Internal Recovery

1) Press and hold ESC and REFRESH + POWER button, A yellow exclamation will be displayed.

2) Press CTRL+D to begin developer mode, then Enter. A red exclamation mark will be displayed.

3) Press CTRL+D. The chrome book deletes its local data, returning to initial state. This takes Approximately 15 Mins.

4) When the transition completes, press the spacebar, then press Enter to return to Verified mode.

5) Enroll the chrome book, before signing into chrome book.

Option 5: Reset chrome book using recovery media

1) Open Google chrome on another working computer and get into web store.

2) In search type recovery utilities and add it to Google chrome.

3) Insert the flash drive or External SD card and click on Create Recovery Media.

4) It will ask for the Model Number (Use SNID to find model Number or follow the next step).

5) Press and hold ESC and REFRESH + POWER button, A yellow exclamation will be displayed.

6) Press CTRL+D to begin developer mode, then Enter. A red exclamation mark will be displayed.

7) At the very bottom on the developer mode you can find the Chrome book exact model number ( Screen shot below).

8) Create recovery media using model number.

9) Creating recovery media will take 15-20 mins. Then follow step 4,5.

10) It will be asking to insert the recovery media. Continue the on screen instruction to install.

11) Then go to verification mode and restart the chrome book.

aukermdr

Hi Jack22,

Thanks for the quick reply. Options 1, 2, and 3 can't be done here because my C720 doesn't boot up correctly - no way to reset or power wash using the regular operating system. Option 5 is what I've already tried - I've created the recovery media, plugged in the flash drive into the C720, and as soon as the verification of the recovery media is complete, the C720 says "an unexpected error has occurred," and nothing else happens.

I didn't know about Option 4's trick of entering Developer Mode. I pressed CTRL+D from the screen with the yellow exclamation mark, and pressed Enter to go into Developer Mode. Pressing CTRL+D again didn't begin the deletion of local data as you described in step 3. I tried inserting the recovery media once again, and the C720 did recognize that it was in developer mode during the verification process. But the same error message ("an unexpected error has occurred") stopped everything once again.

Any other ideas?

David

billsey

It's possible the onboard flash has failed.

aukermdr

billsey said:

It's possible the onboard flash has failed.

Hi billsey,

So if that's the case, is there any way to fix it?

David

billsey

Not really, it's soldered to the motherboard, so takes special skills and equipment to remove without damage. Cheaper to just replace the motherboard or get a new one.

SaltyGaming970

Hi @aukermdr
I have use one of those, but I think that there is a command that when you sign out you should be able to do a fresh install.

Hope someone can find the command

I hope this helps!

wis

Possibility 1:
USB drives configured improperly or thumb drives damaged. Try plugging drive into Windows machine, right click on that drive & reformat it. If it cannot be reformatted, it's broken. Reformatting will wipe it clean. Repeat with different thumb drive if same error message encountered. At Recover Your Chromebook, "What You Need", Step 2 "Download A New Copy of the OS", be certain you choose the correct model of your Acer. I think that C720 is part of the drop-down. If not choose the closest model. I had to choose C7 because there wasn't a choice for C710. Follow all directions slowly & carefully. Don't pull the thumb drive out before you are prompted to do so.

Possibility 2:
You're still in Developer Mode. Here is a pictorial explanation.

After you press Esc + Refresh + Power, do you see this?

then hit the Space bar to exit Developer Mode.

Or do you see this?

then insert reformatted USB drive. You're not in Developer Mode.

If you are back at the login screen, you may still be Developer Mode. This is a rather old video, but @ 1:08 are the instructions of how to launch a command line (Command Prompt in Windows). Copy & paste (click Edit tab & click Paste) the following to exit Developer Mode:

sudo crossytem disable_dev_request=1
sudo reboot

wis

`Edit<br>`

If you are at this screen, hit Space.

Image: https://www.howtogeek.com/wp-content/uploads/2016/11/img_581a4c8c67713.jpg

Hit Enter in this screen. Don't hit Esc, otherwise you'll be back to Developer Mode.

If you are at the setup screen, you may still be in Developer Mode, complete the setup.

Image: http://www.hotspotjournal.com/wp-content/plugins/RSSPoster_PRO/cache/6965d_chromeos-virtualbox-configure-720x720.png

Press Ctrl + Alt + t for the terminal, which will appear as a tab in the Chrome browser. If you are not in Developer Mode, the command line won't appear. Type shell and press Enter. Open another browser tab to navigate back to this webpage. Copy these two commands: