C H A P T E R 6

Checking LEDs

This chapter describes the front-panel and back-panel LEDs, which give the clear status of the operation of all drives and modules. Topics covered in this chapter include:

LEDs When Array Is First Powered On

Front-Panel LEDs

Back-Panel LEDs

6.1 LEDs When Array Is First Powered On

With the array powered on without the SCSI bus configuration cable installed while the array is not connected to a server, you should see the LED conditions described in TABLE 6-1 and TABLE 6-2.


Drive LEDs	Solid green
Chassis ear LEDs	Solid green


I/O Module:
ERROR LED	Blinking green (no bus configuration; invalid state)
TERM LED	Solid green (autotermination enabled)
	Inactive (no bus configuration; invalid state)
Power/fan module LEDs	Solid green

6.2 Front-Panel LEDs

The drive LEDs are located between the rows of drives on the front panel (see the following figure). The system operation LEDs are located on the right ear of the chassis.

FIGURE 6-1 Front-Panel LEDs

Figure showing the LEDs on the front panel.

The following figure shows the front-panel LEDs and Reset button.

Use the Reset button to silence an alarm. For alarm details, see Silencing Audible Alarms.

FIGURE 6-2 Chassis Ear LEDs and Reset Button on Front Panel

Figure showing the Reset button and the following LEDs: power, fan, temp, and event.

The following table lists the front-panel LEDs.


LED	LED Color	Description
Drive	Solid green Blinking green Solid amber	Good: Drive power-up and spin-up OK. Good: Drive activity. Failed: Drive failure.
Power (Light bulb icon) Monitors the DC output voltage within tolerance specification. Overcurrent protection shutting down any voltage output displayed. Voltage thresholds: +5 VDC +/-.25 VDC +12 VDC +/-.6 VDC Current thresholds: +5 VDC 35A +12 VDC 25A	Solid green Solid amber	Power supply good. Failed: One or more output voltages out of range.
Temp (Thermometer icon) Monitors the temperature level and indicates violations of internal temperature thresholds of 55C and 60C.	Solid green Solid amber	Good: Under temperature threshold of 55C. Failed: Temperature threshold equal to or over 55C.
Event (Caution icon) Indicates any abnormal or failure event.	Solid green Solid amber	Normal operation. Abnormal environment event.

Note - To test that the front-panel LEDs work, press and hold the Reset button for 5 seconds. All the LEDs should change from green to amber when you perform this test. Any LED that fails to light indicates a problem with the LED. When you release the Reset button, the LEDs return to their initial state.

6.3 Back-Panel LEDs

The back-panel LED colors indicate the conditions described in the following figures and tables. The following figure is the back-panel with LEDs.

FIGURE 6-3 Back-Panel LEDs

Figure showing the back view of a JBOD array.


Module	LED Color	Status
Power supply/fan Monitors the DC output voltage within tolerance specification. Overcurrent protection shutting down any voltage output will also be displayed. Voltage thresholds: +5 VDC +/-.25 VDC +12 VDC +/-.6 VDC Current Thresholds: +5 VDC 35A +12 VDC 25A	Solid green Solid amber Solid green Solid amber	Power supply good. Failed: one or more output voltages out of range. Good fan: Over 900 RPM. Faulty/failed: Under 900 RPM.
I/O module TERM LEDs ERROR LED	Solid green Inactive LED Blinking green Solid amber Inactive LED	Autotermination enabled. Autotermination disabled. Invalid single- or dual-cable configuration. Failed I/O module. Valid single- or dual-bus configuration, and I/O module is good.

Caution - If you see a blinking green or amber LED, you might have an incorrect configuration or a failed component.

The AC and DC power supply and fan modules have a single LED.

FIGURE 6-4 AC Power Supply and Fan Module

Figure showing the AC power supply and fan module.

FIGURE 6-5 DC Power Supply and Fan Module

Figure showing the DC power supply and fan module.

The I/O modules for JBOD units have TERM and ERROR LEDs.

FIGURE 6-6 JBOD I/O Module