Diagnostic Lights - Dell Dimension 5150 Service Manual

hard drive. The light might also be on when a device such as a CD player is operating.

Diagnostic Lights

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the
Product Information Guide.
To help you troubleshoot a problem, your computer has four diagnostic lights labeled "1," "2," "3," and "4" on the front panel.
When the computer starts normally, the lights flash. If the POST portion of system boot completes successfully, all four lights
display solid green. If the computer malfunctions during the POST process, the pattern displayed on the lights may help
identify where in the process the computer halted.
Light Pattern Problem Description
The computer is in a normal
"off" condition, has successfully
booted to the operating system,
or a possible pre-BIOS failure
has occurred.
A possible processor failure has
occurred.
Memory modules are detected,
but a memory failure has
occurred.
A possible graphics card failure
has occurred.
A possible floppy or hard drive
failure has occurred.
A possible USB failure has
occurred.
No memory modules are
detected.
Memory modules are detected,
but a memory configuration or
Suggested Resolution
Plug the computer into a working electrical outlet and press the power
button. Also see "Power Problems" in your computer Owner's Manual.
Contact Dell (see your computer Owner's Manual for information
about how to contact Dell).
If you have two or more memory modules installed, remove the
modules, reinstall one module, and then restart the computer.
If the computer starts normally, reinstall an additional module.
Continue until you have identified a faulty module or reinstalled
all modules without error.
If available, install properly working memory of the same type
into your computer.
If the problem persists, contact Dell (see your computer
Owner's Manual for information about how to contact Dell).
If the computer has a graphics card, remove the card, and then
restart the computer.
If the problem still exists, install a graphics card that you know
works and restart the computer.
If the problem persists or the computer has integrated
graphics, contact Dell (see your computer Owner's Manual for
information about how to contact Dell).
Reseat all power and data cables and restart the computer.
Reinstall all USB devices, check cable connections, and then restart
the computer.
If you have two or more memory modules installed, remove the
modules, reinstall one module, and then restart the computer.
If the computer starts normally, reinstall an additional module.
Continue until you have identified a faulty module or reinstalled
all modules without error.
If available, install properly working memory of the same type
into your computer.
If the problem persists, contact Dell (see your computer
Owner's Manual for information about how to contact Dell).
Ensure that no special memory module/memory connector
placement requirements exist (see "Memory").
action is
required.