Battery Status Lights; Real Time Clock Reset - Dell Precision 7720 Owner's Manual

The system will not shutdown when displaying the Diagnostic Error Codes. Diagnostic Error Codes will always supersede any other use of
the LED. For instance, on Notebooks, battery codes for Low Battery or Battery Failure situations will not be displayed when Diagnostic
Error Codes are being displayed:
Table 19. LED pattern
Blinking pattern Problem Description
Ambe White
r
2 1 processor
2 2 system board, BIOS ROM
2 3 memory
2 4 memory
2 5 memory
2 6 system board; chipset
2 7 display
3 1 RTC power failure
3 2 PCI/Video
3 3 BIOS recovery 1
3 4 BIOS recovery 2

Battery status lights

If the computer is connected to an electrical outlet, the battery light operates as follows:
Alternately An unauthenticated or unsupported non-Dell AC adapter is attached to your laptop. Re-plug battery connector,
blinking amber replace battery if the issue reoccurs.
light and white
light
Alternately Temporary battery failure with AC adapter present. Re-plug battery connector, replace battery if the issue
blinking amber reoccurs.
light with steady
white light
Constantly Fatal battery failure with AC adapter present. Fetal battery, replace the battery.
blinking amber
light
Light off Battery in full charge mode with AC adapter present.
White light on Battery in charge mode with AC adapter present.

Real Time Clock reset

The Real Time Clock (RTC) reset function allows you to recover your Dell system from No POST/No Boot/No Power situations. To
initiate the RTC reset on the system make sure system is in a power-off state and is connected to power source . Press and hold the
power button for 25 seconds and then release the power button. Go to
NOTE: If AC power is disconnected from the system during the process or the power button is held longer than 40
seconds, the RTC reset process is aborted.
The RTC reset will reset the BIOS to Defaults, un-provision Intel vPro and reset the system date and time. The following items are
unaffected by the RTC reset:
• Service Tag
• Asset Tag
• Ownership Tag
84 Troubleshooting
Suggested Resolution
processor failure
system board, covers BIOS corruption or ROM error
no memory/no RAM detected
memory failure/RAM failure
invalid memory installed
system board/ chipset error
display failure
coin-cell battery failure
PCI/Video card/chip failure
recovery image nor found
recovery image found but invalid
how to reset real time clock.