Checking the Equipment

This section provides troubleshooting procedures for external devices attached to the system, such as the monitor, keyboard, or mouse. Before you perform any of the procedures, see "Troubleshooting External Connections."

Troubleshooting IRQ Assignment Conflicts

Most PCI devices can share an IRQ with another device, but they cannot use an IRQ simultaneously. To avoid this type of conflict, see the documentation for each PCI device for specific IRQ requirements. Table 4-2lists the IRQ assignments.

Table 4-2. IRQ Assignment Defaults

IRQ Line

Assignment

 

 

IRQ0

System timer

IRQ1

Keyboard controller

IRQ2

Interrupt controller 1 to enable IRQ8 through IRQ15

IRQ3

Available

IRQ4

Serial port 1 (COM1 and COM3)

IRQ5

Remote access controller

IRQ6

Diskette drive controller

IRQ7

Available

IRQ8

Real-time clock

IRQ9

ACPI functions (used for power management)

IRQ10

Available

IRQ11

Available

IRQ12

PS/2 mouse port unless the mouse is disabled through the System Setup program

IRQ13

Math coprocessor

IRQ14

IDE optical drive controller

IRQ15

Available

 

 

Troubleshooting the Video Subsystem

Problem

•Monitor is not working properly.

•Video memory is faulty.

92Troubleshooting Your System