Xserve: Won‘t Start Up, Activity Lights Flash Three Times

Learn what it means if the activity lights flash three times when you try to start up your server.
Symptom

The server does not start up; the activity lights flash three times when you try to start the server.

Solution

When the activity lights flash three times, this means that incompatible RAM is probably installed.

Install the correct memory:
Xserve PC2100 DDR
Xserve (Slot Load) PC2700 DDR
Xserve (Cluster Node) PC2700 DDR


Check the installed memory

  1. If the SDRAM appears to be the correct type, check the server using Apple Hardware Test. If the test finds bad memory, replace it (one DIMM at a time) with known good SDRAM and repeat the test until it reports that every DIMM is OK.
  2. If all DIMMs are known good memory and the issue still occurs, the logic board may need to be replaced.


Note: When installing the replacement logic board, make sure the ports and ID button on the back of the board align with the opening in the chassis.
Published Date: Feb 20, 2012