Dell Latitude 7420 Service Manual page 5

Built-in self-test (BIST)................................................................................................................................................... 79
M-BIST........................................................................................................................................................................... 79
LCD Power rail test (L-BIST)................................................................................................................................... 80
LCD Built-in Self Test (BIST)................................................................................................................................... 80
System-diagnostic lights.................................................................................................................................................. 81
Recovering the operating system................................................................................................................................. 82
Real-Time Clock (RTC Reset)........................................................................................................................................82
Backup media and recovery options.............................................................................................................................83
Wi-Fi power cycle..............................................................................................................................................................83
Drain residual flea power (perform hard reset)......................................................................................................... 83
Chapter 6: Getting help and contacting Dell................................................................................ 85
Contents 5