Dell OptiPlex 740 - Manual (Page 189)

Fan Problems
Lockups and Software Problems
The computer does not start up
The computer stops responding
A program stops responding
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions located in the Product Information Guide.
Check the keyboard cable —
l Ensure that the keyboard cable is firmly connected to the computer.
l Shut down the computer, reconnect the keyboard cable as shown in the Quick Reference Guide for your computer, and then restart the
computer.
l Check the cable connector for bent or broken pins and for damaged or frayed cables. Straighten bent pins.
l Remove keyboard extension cables and connect the keyboard directly to the computer.
Test the keyboard — Connect a properly working keyboard to the computer, and try using the keyboard. If the new keyboard works, the
original keyboard is faulty.
Run the Dell Diagnostics — See Dell Diagnostics .
Check for software and hardware conflicts — See Resolving Software and Hardware Incompatibilities .
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before opening the cover.
NOTICE: To prevent static damage to components inside your computer, discharge static electricity from your body before you touch any of your
computer's electronic components. You can do so by touching an unpainted metal surface on the computer.
Check the cable connections — Ensure that the card fan cable is connected firmly to the card fan connector on the system board (see
System Board Components for mini tower computers, and System Board Components for desktop computers).
CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
Check the Diagnostic Lights — See Diagnostic Lights .
Ensure that the power cable is firmly connected to the computer and to the electrical outlet
NOTICE: You might lose data if you are unable to perform an operating system shutdown.
Turn the computer off — If you are unable to get a response by pressing a key on your keyboard or moving your mouse, press and hold
the power button for at least 8 to 10 seconds until the computer turns off. Then restart your computer.