Dell OptiPlex 755 User Manual
Page 245
Bus type
SATA 1.0a and 2.0;
USB 2.0
Bus speed
SATA: 1.5 and 3.0 Gbps;
USB: 480 Mbps
Drives
Internal/External
one D-module bay for an optical drive, second hard
drive, or floppy drive
one bay for a 3.5-inch hard drive
Connectors
External connectors:
Serial
9-pin connector; 16550C-compatible
Parallel
25-pin connector (bidirectional)
Video
28-pin DVI connector
Network adapter
RJ45 connector
USB
two front-panel and five back panel USB 2.0–
compliant connectors
Audio
two back panel connectors for line-in and line-out;
two front-panel connectors for headphones and
microphone
System board connectors:
SATA
7-pin connector
Fan
one 3-pin and two 5-pin connectors
Key Combinations
<Ctrl><Alt><Del>
in Microsoft® Windows® XP, brings up the Windows
Security window; in MS-DOS® mode, restarts
(reboots) the computer
<F2> or <Ctrl><Alt><Enter>
starts embedded system setup (during system start-
up only)
<F3>
automatically starts the computer from the network
environment specified by the remote boot
environment (PXE) rather than from one of the
devices in the system setup Boot Sequence option
(during start-up only)
<F12> or <Ctrl><Alt><F8>
displays a boot device menu that allows the user to
enter a device for a single boot (during system start-
up only) as well as options to run hard drive and
system diagnostics
<Ctrl><p>
displays the Management Engine BIOS Extension
settings screen that allows you to modify the settings
Controls and Lights
Power control
push button
Power light
green light — Blinking green indicates a sleep mode;
solid green indicates the power-on state.
amber light — Blinking amber indicates a problem
with an installed device; solid amber indicates an
internal power problem (See
Power Problems
.)
Power supply status light
green light — Solid green indicates the power
adapter is connected to an AC outlet and the
computer.
amber light — Solid amber indicates the power
adapter is connected to an AC outlet but not the
computer.
hard drive access light
green
Link integrity light (on integrated network adapter)
green light for 10-Mb operation; orange light for 100-
Mb operation; yellow light for a 1000-Mb (1-Gb)
operation
Activity light (on integrated network adapter)
yellow blinking light
Diagnostic lights
four lights on the back panel (See
Diagnostic Lights
.)
Standby power light
AUX_PWR on the system board