Troubleshooting Your Computer; Diagnostic Leds - Dell Precision Tower 7910 Owner's Manual

Troubleshooting Your Computer

You can troubleshoot your computer using indicators like Diagnostic Lights, Beep Codes, and Error
Messages during the operation of the computer.

Diagnostic LEDs

NOTE: The diagnostic LEDs only serve as an indicator of the progress through the Power-On Self
Test (POST) process. These LEDs do not indicate the problem that caused the POST routine to stop.
The diagnostic LEDs are located on the front of the chassis next to the power button. These diagnostic
LEDs are only active and visible during the POST process. Once the operating system starts to load, they
turn off and are no longer visible.
Each LED has two possible states of OFF or ON.
NOTE: The diagnostic lights will blink when the power button is amber or off, and will not blink
when it is white.
Table 14. POST Diagnostic LED Patterns
Power LED State System State
Off S5/S4
Blinking White S3
Blinking Amber N/A
Steady White S0
Steady Amber N/A
NOTE: Amber LED blinking schemepattern is 2 or 3 blinks followed by a short pause then X number
of blinks up to 7. Pattern has a long pause inserted in the middle. For example 2,3 = 2 amber blinks,
short pause, 3 amber blinks followed by long pause then repeats.
Table 15. POST Diagnostic LED Patterns
Blink Patter
2,1
2,2
68
Notes
Normal- System is Off/Hibernate
Normal- System is in Standby/Suspend
Abnormal- PSU cannot turn on, recommend PSU BIST.
Replace PSU.
Normal- System is on functioning
Abnormal- System cannot turn on, recommend check
motherboard components or replace motherboard.
System State
A possible system motherboard
failure has occurred.
A possible PSU or cabling issue
has occurred.
Notes
Recommend replace
motherboard.
Run PSU BIST.
6