Product data
Subsystem Lights
To identify the lights that are described here, see Figures 2 and 3.
The Subsystem Power light and Subsystem Check light are located on the backplane
assembly. The lights are made visible by light pipes that pass through the bezel at the
front of the 2104.
Subsystem Power light 1: This green light is on continuously when dc voltage is
present in the 2104.
Subsystem Check light 2: This amber light comes on continuously if a failure occurs
in the 2104. The 2104 might be able to continue operating satisfactorily although the
failure of a particular part has been detected. The light flashes when a service aid
identifies a disk drive module.
Note: The Subsystem Check light comes on only when dc voltage is present in the
2104.
SCSI Interface Card Lights
To identify the lights that are described here, see Figures 2 and 3.
TERM POWER light 3: This green light is on when the ‘TERMPWR’ signal is present
on the external SCSI connector, and the voltage is correct.
LVD/SE light 4: This green light is on for differential SCSI operation, and off for
single-ended SCSI operation.
ACTIVE light 5: This green light is on when a SCSI command is in progress.
SCSI RESET light 6: This green light comes on when a ‘power-on reset’ (POR)
signal or a ‘SCSI bus reset’ signal occurs.
CARD FAULT light 7: This amber light comes on if the SCSI interface card fails.
Chapter 1. Reference Information 7