Control Lights And Diagnostic Lights - Dell OptiPlex 990 Setup And Features Information

Drives
2.5 inch SATA drive bays

Control Lights And Diagnostic Lights

Front of computer
Power button light
Drive activity light
Diagnostic lights
Back of computer
Power supply light
10
• Mini Tower — two
• Desktop — one
• Small Form Factor — one
• Ultra Small Form Factor — one
Blue light — Solid blue light indicates power-on
state; blinking blue light indicates sleep state of the
computer.
Amber light — Solid amber light when the computer
does not start indicates a problem with the system
board or power supply. Blinking amber light indicates
a problem with the system board.
Blue light — Blinking blue light indicates that the
computer is reading data from or writing data to the
hard drive.
Four lights located on the front panel of the
computer. For more information on the diagnostic
Service Manual at support.dell.com/
lights, see the
manuals.
Green light — The power supply is turned on and is
functional. The power cable must be connected to
the power connector (at the back of the computer)
and the electrical outlet.
NOTE: You can test the health of the power
system by pressing the test button. When the
system power supply voltage is within
specification, the self-test LED lights up. If the
LED does not light up, the power supply may be
defective. AC power must be connected during
this test.