User Guide

Mac Pro (8x) Troubleshooting — General Information 143
Interface (EFI) operations and the operating system is now in control.
Troubleshooting:
Check that LED 7 Power On LED is on. •
Check that LEDs 2, 3, 4, and 5 are o. •
Try removing any added hardware. •
Try removing any added DIMMs. •
Memory Riser Card Diagnostic LEDs
Both of the memory riser cards include diagnostic LEDs for each DIMM. Each of the LEDs will
light if it detects an issue with the corresponding installed DIMM. These LEDs will also ash briey
when the computer is started up or shut down and when it goes in and out of sleep mode. This
is normal behavior.
Troubleshooting:
Shutdown and restart the computer. •
Verify EFI and SMC rmware versions and update them if necessary. See “• Mac Pro Firmware
Updates” in this section for more information.
Reseat the memory riser card associated with the failure LED. If the failure LED persists, •
continue with the next step.
Swap upper and lower memory riser cards A and B. If the symptoms follow the riser card, •
continue with the next step. If the failure LED remains associated with the same memory
riser card slot, consider a possible connection issue with the logic board. Replace the logic
board in this case.
Reseat the appropriate DIMM corresponding to the failure LED. If the issue persists, continue •
with the next step.
Check memory installation instructions for proper installation order. •
Swap aected DIMM with known good DIMM.•
Try moving DIMM to another slot (within the same bank of two) to see if the failure LED •
follows the DIMM. If so, replace DIMM with known good DIMM. If the failure LED persists,
replace the memory riser card associated with the failure LED.
Video Card Diagnostic LEDs
T_Fault LED
Normally o, this LED lights up if the graphics chip gets too hot.
Troubleshooting:
Verify that the video card heatsink and fan are not clogged with dust. Carefully blow out any •
dust as necessary.
Check that the front fan is working. •
Try re-seating the card in the PCI Slot. •
Make sure the card’s auxiliary booster power cable is connected (if there is one). •
Re-boot the computer. •
Try a dierent video card. •