Wifi Power Cycle; Bios Recovery - Dell Latitude 5424 Rugged Service Manual

Table 29. LED pattern (continued)
Blinking pattern
Green
3
3
3
3

WiFi power cycle

If your computer is unable to access the Internet due to WiFi connectivity issues, a WiFi power cycle procedure may be
performed. The following procedure provides the instructions on how to conduct a WiFi power cycle:
NOTE: Some ISPs (Internet Service Providers) provide a modem/router combo device.
1. Turn off your computer.
2. Turn off the modem.
3. Turn off the wireless router.
4. Wait for 30 seconds.
5. Turn on the wireless router.
6. Turn on the modem.
7. Turn on your computer.

BIOS recovery

The BIOS recovery is designed to fix the main BIOS, and cannot work if the boot is damaged. The BIOS recovery will not work
in the event of EC corruption, ME corruption, or a hardware related issue. The BIOS recovery image should be available on the
unencrypted partition on the drive for BIOS recovery feature.
Rollback BIOS feature
Two versions of the BIOS recovery image are saved on the hard drive:
● Current running BIOS (old)
● To-be-updated BIOS (new)
The old version is already stored on the hard drive. The BIOS adds new version to the hard drive, maintains the old version, and
deletes other existing versions. For example, A00 and A02 versions are already on the hard drive, A02 is the running BIOS. The
BIOS adds A04, maintains A02, and deletes A00. Having two BIOS version enables the Rollback BIOS feature.
If the recovery file cannot be stored (hard drive is out of space), the BIOS sets a flag to indicate this condition. The flag is reset
in the event it later becomes possible to store the recovery file. The BIOS notifies the user during POST and in BIOS Setup, the
BIOS recovery is degraded. BIOS recovery through hard drive may not be possible, however BIOS recovery through USB flash
drive is still possible.
For USB key: root directory or "\"
BIOS_IMG.rcv: the recovery image stored on the USB key.
White
4
5
6
7
Problem Description
BIOS recovery 2
Power Rail Failure
SBIOS Flash Corruption
ME Error
Suggested Resolution
Recovery image found but
invalid
EC ran into power
sequencing failure
Flash corruption detected
by SBIOS
Timeout waiting on ME to
reply to HECI message
Diagnostics 165