User Guide

Mac Pro Troubleshooting — Symptom Charts 156
Reset logic board. Refer to “3. Resetting the Logic Board” in this chapter.
Verify power supply cables are properly seated4. .
Check diagnostic LED 2 and/or LED 3 for processor connection 5.
If only one of the CPU Error LEDs (LED 2 or 3) comes on, try swapping the processors. If the 6.
Error LED follows the processor to the other processor location, replace that processor.
Replace logic board 7.
Power-on LED illuminates when power button is pressed, fans spin, and boot tone
chimes, but there is no video
Verify display is properly connected and powered on.1.
Check video card connector and display cable for any bent pins.2.
Reseat video card. (Make sure video card is fully inserted in connector and end of card is 3.
secured by the connector latch.) For video cards that require power cables, check that they
are connected.
Reset PRAM (restart computer while holding down Command-Option-P-R keys until second 4.
boot tone chimes)
Reset logic board. Refer to “5. Resetting the Logic Board” in this chapter.
Verify power supply cables are properly seated6. .
Replace video card 7.
Replace logic board 8.
Power-on LED does not illuminate when power button is pressed, but fans spin,
boot tone chimes, and there is video
Verify power supply cables are properly seated1. .
Reseat front panel board 2.
Replace front panel board 3.
Replace logic board 4.
Replace power supply 5.
Power-on LED illuminates, fans spin up, no boot tone, and the system shuts down
within a few minutes
Open the side access panel and observe all diagnostic LEDs. Refer to “1. Diagnostic LEDs” in
this chapter for more information on how to locate and interpret these LEDs. Troubleshoot
further if any LEDs indicate any failure.
Verify power supply cables are properly seated2. .
Reseat the processors and check for bent pins 3.