Dell 840 Personal Computer User Manual


 
92 Troubleshooting Your System
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 4-2 lists the IRQ assignments.
Troubleshooting the Video Subsystem
Problem
Monitor is not working properly.
Video memory is faulty.
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