Powerwashing 3110s
The process is a little different for new chromebooks
Step 1: Use regular key combination (power, esc and refresh keys)
Step 2: This screen will appear
Step 3: Use arrow keys and then enter to select ADVANCED OPTIONS
Step 4: Select ENABLE DEVELOPER MODE by pressing ENTER
Step 5. It will ask you if you’re sure you want to do this. Select yes by pressing ENTER on CONFIRM.
Step 6: It will warn you again. Select CONFIRM by pressing ENTER.
Step 7: Now you can powerwash it as usual.