Debugging system hangs (go/cros-debug-hang)
If your Chromebook appears hung (i.e. the screen is frozen and the keyboard and/or trackpad are unresponsive), try the following steps:
- Pre-Recovery Steps
- Note any visible system indicators like LEDs. Are they blinking or solid. What color?
- Note charging/discharging behavior if possible. Does plugging a charger in change LED.
- Note USB response. Does touching an gnubby blink. Does charging a phone via a USB port work?
- Recovery Steps
- Press Alt+VolumeUp+X. If you're using a Chromebox, use F10
instead of VolumeUp. These three keys need to be pressed in that
- This should cause the Chrome browser to restart, and it may take a few seconds. If the system becomes responsive, go to last step.
- Press Alt+VolumeUp+X a second time.
- This should cause the kernel to panic-reboot. If the system becomes responsive, go to last step.
- Press Alt+VolumeUp+R which should cause a warm reset & reboot. If so, go to last step. (This may not work on older hardware.)
- Press and hold the power button for 8+ seconds and the system will power off (if shutdown is clean) or it will reboot via EC reset
- Press Refresh+Power button(F3). This causes an EC reset on most systems and should be used only as a last resort as it minimizes the amount of available debug info.
- Press Alt+VolumeUp+X. If you're using a Chromebox, use F10 instead of VolumeUp. These three keys need to be pressed in that order.
- Last Step
- Power on (if necessary) Log in, and immediately file feedback
- Make sure that "Send system and app information" is checked.
- Make sure to identify what recovery steps you used including the ones you believed failed.
- Power on (if necessary) Log in, and immediately file feedback using Alt+Shift+i.
You may also be able to see crash report IDs at chrome://crashes.
For a complete and up-to-date list of debug key sequences including those for ChromiumOS devices without a keyboard check here.