Dell OptiPlex 390 Owner's Manual page 72

LED
Power Button
Problem Description
Troubleshooting Steps
LED
Power Button
Problem Description
Troubleshooting Steps Re-install all USB devices and check all cable
LED
Power Button
Problem Description No memory modules are detected.
Troubleshooting
Steps
72
• If available, install working memory of the same type
into your computer.
A possible hard drive failure has occurred.
Re-seat all power and data cables.
A possible USB failure has occurred.
connections.
• If two or more memory modules are installed,
remove the modules (see your service manual), then
reinstall one module (see your service manual) and
restart the computer. If the computer starts normally,
continue to install additional memory modules (one
at a time) until you have identified a faulty module or
reinstalled all modules without error.