Dell Precision T7400 (Late 2007): Diagnostic Lights Diagnostic Light Codes During POST Light Pattern Problem Description Suggested Resolution
Diagnostic Lights Diagnostic Light Codes During POST Light Pattern Problem Description Suggested Resolution: Dell Precision T7400 (Late 2007)
Table of contents
- Notes, Notices, and Cautions
- Contents
- Finding Information What Are You Looking For? Find It Here
- What Are You Looking For? Find It Here
- What Are You Looking For? Find It Here
- What Are You Looking For? Find It Here
- What Are You Looking For? Find It Here Setting Up Your Computer Changing Between Tower and Desktop Orientations Switching From Tower to Desktop Orientation
- Switching From Desktop to Tower Orientation Installing Your Computer in an Enclosure
- • Leave 10.2 cm (4 in) minimum clearance on all vented sides of the computer to permit the airflow required for proper ventilation.
- • Do not install your computer in an enclosure that does not allow airflow.
- Transferring Information to a New Computer Microsoft Windows XP
- Files and Settings Transfer Wizard (With the Operating System Disc) PREPARE THE DESTINATION COMPUTER FOR THE FILE TRANSFER — COPY DATA FROM THE SOURCE COMPUTER —
- TRANSFER DATA TO THE DESTINATION COMPUTER — Files and Settings Transfer Wizard (Without the Operating System Disc) CREATE A WIZARD DISK — COPY DATA FROM THE SOURCE COMPUTER —
- TRANSFER DATA TO THE DESTINATION COMPUTER — Microsoft Windows Vista Power Protection Devices
- Surge Protectors Line Conditioners Uninterruptible Power Supplies
- About Your Computer Front View (Tower Orientation) 1–3 5.25-inch drive bays
- 13 network link light The network link light is on when a good connection exists
- Back View (Tower Orientation)
- Back Panel Connectors 6 link integrity light Green — A good connection exists between a 10-Mbps
- 11 serial connectors (2)
- Cleaning Your Computer Computer, Keyboard, and Monitor Mouse (Non-Optical)
- Floppy Drive CDs and DVDs Troubleshooting Tools Power Lights
- • Eliminate interference. Some possible causes of interference are:
- Diagnostic Lights Diagnostic Light Codes During POST Light Pattern Problem Description Suggested Resolution
- Light Pattern Problem Description Suggested Resolution
- Light Pattern Problem Description Suggested Resolution
- Light Pattern Problem Description Suggested Resolution
- Beep Codes Code Cause Code Description Suggested Remedy
- Code Description Suggested Remedy System Messages
- Hardware Troubleshooter
- Dell Diagnostics When to Use the Dell Diagnostics Starting the Dell Diagnostics From Your Hard Drive
- Starting the Dell Diagnostics From the Drivers and Utilities Disc
- Dell Diagnostics Main Menu Option Function
- Tab Function Troubleshooting
- Battery Problems Drive Problems
- Optical Drive Problems Hard Drive Problems
- E-Mail, Modem, and Internet Problems HECK THE MICROSOFT OUTLOOK EXPRESS SECURITY SETTINGS — If you cannot RUN THE MODEM DIAGNOSTIC TOOL —
- VERIFY THAT THE MODEM IS COMMUNICATING WITH WINDOWS — Error Messages
- IEEE 1394 Device Problems
- Keyboard Problems Lockups and Software Problems The computer does not start up The computer stops responding A program stops responding
- A program crashes repeatedly A program is designed for an earlier Windows operating system A solid blue screen appears Other software problems
- Memory Problems F YOU RECEIVE AN INSUFFICIENT MEMORY MESSAGE — IF YOU EXPERIENCE OTHER MEMORY PROBLEMS — Mouse Problems C HECK THE MOUSE CABLE —
- RESTART THE COMPUTER — HECK THE MOUSE SETTINGS — Network Problems
- Power Problems
- Printer Problems Scanner Problems
- Sound and Speaker Problems
- No sound from headphones Video and Monitor Problems The screen is blank
- The screen is difficult to read
- 3D image quality is poor Only part of the screen is readable

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 (see "Front View (Tower Orientation)" on page 18). When
the computer starts normally, the lights flash, and then turn off. If the computer
malfunctions, use the sequence of the lights to help identify the problem.
NOTE: After the computer completes POST, all four lights turn off before booting to
the operating system.
Diagnostic Light Codes During POST
Light Pattern Problem Description Suggested Resolution
The computer is in
Plug the computer into a working
a normal off
electrical outlet and press the
condition or
power button.
a possible pre-BIOS
failure has occurred.
A possible BIOS
• Run the BIOS Recovery utility, wait
failure has occurred;
for recovery completion, and then
the computer is in the
restart the computer.
recovery mode.
• If the problem persists, contact Dell
(see
"Contacting Dell" in your
User’s Guide
).
A possible processor
• Reseat the processor (see "Processor"
failure has occurred.
in your User’s Guide
).
• If the problem persists, contact Dell
(see
"Contacting Dell" in your
User’s Guide
).
26 Quick Reference Guide

