Dell OptiPlex 755 - Manual (Page 66)

66
Quick Reference Guide
Diagnostic Lights
CAUTION:
Before you begin any of the procedures in this section, follow the
safety instructions in the Product Information Guide.
To help troubleshoot a problem, your computer has four lights labeled 1, 2, 3,
and 4 on the front panel. When the computer starts normally, the lights flash
before turning off. If the computer malfunctions, the sequence of the lights
help to identify the problem.
NOTE:
After the computer completes POST, all four lights turn off before booting to
the operating system.
Solid green and a
beep code during
POST A problem was detected while
the BIOS was executing. See "Beep Codes" on page 70 for
instructions on diagnosing the
beep code. Also, check the
diagnostic lights to see if the
specific problem is identified
(see "Diagnostic Lights" on
page 66).
Solid green
power light and
no beep code
and no video
during POST The monitor or the graphics
card may be faulty or incorrectly
installed. Check the diagnostic lights to
see if the specific problem is
identified (see "Diagnostic
Lights" on page 66).
See "Video and Monitor
Problems" in the User’s Guide.
Solid green
power light and
no beep code but
the computer
locks up during
POST An integrated system board
device may be faulty. Check the diagnostic lights to
see if the specific problem is
identified (see "Diagnostic
Lights" on page 66). If the
problem is not identified,
contact Dell for technical
assistance (see "Contacting
Dell" in the User’s Guide).
Power Light Problem Description Suggested Resolution