If surveillance is enabled, the Service Processor provides a 'processor-well' checking function for the node. If a processor fails to perform for a length of time, it is assumed by the Service Processor to be hung. The Service Processor posts an LCD code of 40B00000. If this condition occurs, call IBM hardware service, or consult the hardware manual for a procedure to collect pertinent data from the Service Processor.
For more information about surveillance, see the heading "Service processor system monitoring - surveillance" of "Chapter 3, Service procedures" in RS/6000 SP: POWER3 SMP High Node Service Guide.