The front panel and internal field-replaceable unit (FRU) light-emitting diodes (LEDs) are used in order to help diagnose a server failure. When an internal component fails, the indication is made on an internal component amber LED and on the front panel. If the item is serviceable without the removal of the server hood, as in the case of a redundant power supply failure, the External Health LED illuminates. If the item is serviceable with removal of the hood, as in the case of a fan failure, the Internal Health LED illuminates. If no failures occur, the system health LEDs are green. If a failure occurs, but a redundant feature enables the system to run anyway, the LED is amber. If the failure is critical and causes the system to shutdown, the LED is red. These LEDs serve as local indicators for several failure conditions. Insight Manager continues to report these, and many other failure conditions, as well.
Unit Identification light (UID - Blue):
The Unit Identification light (UID) is a feature of all DL servers that helps to distinguish which server is worked on in the rack. The UID can be lit from the Common Information Model (CIM) console, as well as at the server. In order to do this, press either the front or rear UID button. Once lit, the LED is blue to help identify the unit.
Refer to Problems with Hardware for more information.