Dell Chromebook 5190 Owner's Manual page 74

Checking network status
If you are having trouble connecting to the Internet, use the steps in one or more of the following sections to test the network adapter:
Follow the instruction to gather the information about the network and diagnose the network errors.
1 Turn on and sign in to Chromebook.
2 Open the Chrome browser.
3 Press CTRL + ALT + T to open CROSH.
4 Type network_diag into CROSH, and then press Enter.
74 Diagnostic and troubleshooting