Specifications

4-8 Compaq ProLiant 5500 and 5500R Maintenance and Service Guide
For use with Pentium II and Pentium III Xeon processor-based servers only
System Board Interlock LED Indicators
The Compaq ProLiant 5500 and 5500R server interlock system prevents power distribution
throughout the system if the memory board, processors, or Peripheral Board (including the
power switch cable) are not fully installed or properly seated. ProLiant 5500 and 5500R servers
are not equipped with chassis interlocks; the board interlocks provided connect the memory
board, processors, and Peripheral Board (including the power switch cable) in one interlock
chain. When one of the connected components in the interlock chain is improperly seated in the
connector, the LED associated with the fault origination point illuminates. The ProLiant 5500
and 5500R system board LEDs are illustrated below. See Table 4-7 for the interlock system
LED indicators.
CPU4 CPU3 CPU2 CPU1 I/O
GENERAL
INTERLOCK
FAULT
MEMORY
Figure 4-7. System board interlock LEDs
Table 4-7
System Board Interlock LED Indicators
LED Labels
Memory CPU4 CPU3 CPU2 CPU1 I/O Faulty Device
ON ON ON ON ON ON
Memory Board
OFF
ON ON ON ON ON
Processor 4
OFF OFF
ON ON ON ON
Processor 3
OFF OFF OFF
ON ON ON
Processor 2
OFF OFF OFF OFF
ON ON
Processor 1
OFF OFF OFF OFF OFF
ON
Peripheral Board
OFF OFF OFF OFF OFF OFF No interlock error
NOTE: Only the left-most illuminated LED in any given row can provide a valid indication of the interlock error. After
ensuring the server is powered down and power cables are disconnected, reseat the device associated with the left-
most illuminated LED.