146 | Troubleshooting Your System
10 Reconnect the system to the electrical outlet, and turn on the system
and attached peripherals.
If the problem persists, the processor is faulty. See "Getting Help" on
page 162.
11 Turn off the system and attached peripherals, and disconnect the
system from the electrical outlet.
12 Remove the system-board assembly. See "Removing a System-Board
Assembly" on page 68.
13 Replace processor 1 with processor 2. See "Installing a Processor" on
page 73.
14 Repeat step 9 through step 11.
If you have tested both the processors and the problem persists, the
system board is faulty. See "Getting Help" on page 162.
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.
Tabl e 4 -1. Assignment Specific IRQ Requirements
IRQ
Line
Assignment IRQ
Line
Assignment
IRQ0 8254 timer IRQ8 RTC
IRQ1 Keyboard controller IRQ9 SCI
IRQ2 Cascade for IRQ9 IRQ10 USB controller, NIC
IRQ3 Serial port IRQ11 VGA, USB controller
IRQ4 Serial port IRQ12 Mouse controller
IRQ5 Free IRQ13 Processor
IRQ6 Free IRQ14 Primary IDE controller
IRQ7 USB controller IRQ15 Secondary IDE controller