If your system is not working as expected, begin troubleshooting using the procedures in this section. This section guides you through some initial checks and
procedures that can solve basic system problems and provides troubleshooting procedures for components inside the system. Before you start any of the
procedures in this section, take the following steps:

Read the "Safety Instructions" in your System Information document.

Read "

Running System Diagnostics

" for information about running diagnostics.

Get the key to the system keylock and the system back cover.

Safety First—For You and Your System

The procedures in this guide require that you remove the cover and work inside the system. While working inside the system, do not attempt to service the
system except as explained in this guide and elsewhere in your system documentation. Always follow the instructions closely. Ensure that you review all of the
procedures in "Safety Instructions" in your System Information document.

Working inside the system is safe—if you observe the following precautions.

Before You Begin

Before you perform any of the procedures, ensure that the following components are securely and properly installed:

Power cables

Cables to external devices, such as monitor, mouse, keyboard, and so on

System board tray

Expansion-card cage

External Connections

Improperly set switches, controls, and loose or improperly connected cables are the most likely source of problems for the system, monitor, or other
peripherals (such as a printer, keyboard, mouse, or other external equipment). A quick check of all the switches, controls, and cable connections can easily

CAUTION:

The power supplies in this system produce high voltages and energy hazards, which can cause bodily harm. Only trained service

technicians are authorized to remove the system cover and access any of the components inside the system.

NOTICE:

See "Protecting Against Electrostatic Discharge" in the safety instructions in your System Information document before performing any

procedure which requires you to open the cover.