Sun Enterprise 6500/5500/4500 Systems Reference Manual

Hardware Indicator LEDs

LEDs indicate system status. The front panel and the boards have three LEDs (Figure 9-2). Power supply modules have two LEDs.

Figure 9-2 LED Symbols

The LEDs on the system front panel or the clock+ board indicate the status of the system as a whole. The LEDs on individual boards and power supplies indicate the status of the individual board or power supply. Many of the LED codes (Table 9-1) are common to the system front panel and various types of boards. Table 9-2 lists specific exceptions for LED codes for system boards.

System Front Panel LEDs

Table 9-1 lists the LED codes for system operations.

Table 9-1 System Status Codes


Power	Service	Cycling	Condition
Off	Off	Off	No power or the key switch is in the Off position.
Off	On	Off	Failure mode. System has electrical power.
Off	Off	On	Failure mode. System has electrical power.
Off	On	On	Failure mode. System has electrical power.
On	Off	Off	System is hung, either in POST/OBP or in the operating system.
On	Off	On	Hung in OS.
On	On	Off	(Hung in POST/OBP) or (hung in OS and failed component in system).
On	On	On	(Hung in POST/OBP) or (hung in OS and failed component in system).
On	Off	Flashing	OS running. System is operating normally.
On	On	Flashing	OS running and failed component in system.
On	Flashing	Off	Slow flash = POST. Fast flash = OBP.
On	Flashing	On	OS or OBP error.

LEDs in the system are controlled by OpenBoot(TM) PROM programming (OBP).

Clock+ Board LEDs

The clock+ board also displays system status. The LED codes are the same as for the front panel (Table 9-1).

CPU/Memory+ and I/O+ Board LEDs

Table 9-2 summarizes LED codes for boards. The Power, Service, and Cycling symbols are marked on the card cage frame above the respective LEDs. Note that many but not all of the LED codes are the same as the system codes (Table 9-1).

Table 9-2 Board Status LED Codes


Power	Service	Cycling	Condition
Off	Off	Off	Board has no electrical power.
Off	On	Off	Board is in low-power mode, can be unplugged.
Off	Off	Flashing	Undefined.
Off	On	Flashing	Undefined.
On	Off	Off	System is hanging, either in POST/OBP or OS.
On	Off	On	Hung in OS.
On	On	Off	(Hung in POST/OBP) or (hung in OS and failed component on board).
On	On	On	(Hung in POST/OBP) or (hung in OS and failed component on board).
On	Off	Flashing	OS running. System is operating normally.
On	On	Flashing	OS running and failed component on board.
On	Flash	Off	Slow flash = POST. Fast flash = OBP.
On	Flash	On	OS or OBP error.

Note -

For boards, Off-On-Off indicates that the board is in low-power mode and is ready for removal. (For the system, Off-On-Off indicates a failure.)

Caution -

If the Power LED is lit, do not remove the board. Removing a board that is not in low-power mode will damage the board and the system.

Basic Troubleshooting for Boards

If the yellow LED (middle LED) is continuously lit (not flashing) the board requires service.

If the left and right green LEDs are off, the board is ready for removal.

If no LEDs are flashing, the system is hung.

If no LEDs are lit, there is no electrical power to the board.

Disk Board LEDs

The board status LED codes correspond to those shown in Table 9-2 for the CPU/Memory+ and I/O+ boards. The Disk board has two additional LEDs on the opposite side of the board to show the status of the two onboard disk drives. The LED for disk drive 1 is nearer to the side of the Disk board, and the LED for disk drive 0 is closer to the center of the board.

Power Supplies

A system has one peripheral power supply and up to four or eight CPU/IO modular power supplies. All the power supplies have one green LED and one yellow LED.

The control and status signals of all power supply modules connect to the clock+ board. If the clock+ board LEDs indicate a problem, inspect the LEDs on the power supplies to locate a faulty module, if any.

Peripheral Power Supply (PPS)

The green LED is to the right of the yellow LED on the peripheral power supply. The green LED indicates that the peripheral power supply is operating, but does not necessarily indicate that the DC outputs are within specification.

When the peripheral power supply module yellow LED is lit, a DC power output has malfunctioned or the voltage level is out of specification.

The peripheral power supply produces +5 VDC and +12 VDC current. The current is available for peripherals such as a tape drive and/or CD-ROM drive. In addition, the +5 VDC output of the peripheral power supply is available at the center plane for current sharing with the +5 VDC outputs of the power supply modules.

Power/Cooling Modules (PCMs)

For a PCM at the front of the card cage, the green LED is to the left of the yellow LED. At the back of the card cage, the LED positions are reversed and the green LED is to the right of the yellow LED. See Table 9-3.

When the yellow LED is lit, a fan or a DC output has malfunctioned. Each modular power supply contains two fans and three DC supplies (+3.3 VDC, +5 VDC, and +2 VDC).

The green LED indicates that the DC supplies are operating, but does not guarantee that the DC outputs are within specification.

Table 9-3 Modular Power Supply LED Codes


Green	Yellow	Condition
Off	Off	No AC input or key switch is turned off.
On	Off	Normal operation.
On	On	A fan has failed or one or more voltages are out of specification.
Off	On	One or more DC outputs have failed, or the voltages are out of specification, or the system is in the low power state.

The PCMs operate in redundant current share mode. If a module fails, the remaining modules may or may not provide enough current to continue system operation. The system's ability to continue operations depends on the total demand for current.

Disk Tray Indicators

The availability and type of status information varies with the disk tray type used in a system. Refer to the disk tray user manual for specific status information.