CPU/Memory+ and I/O+ Board LEDs

Most of the codes for the CPU/Memory+ and I/O+ board LEDs are similar to codes for the front panel and clock+ board. The major exception is the second code (Off-On-Off). For hot-pluggable boards, this code indicates that the board is in low power mode and is ready to remove.

---

Caution -

If the Running LED is lit or flashing, do not remove the board. Electrical shorting will result, damaging the board and the system.

---

Table 9-2 lists all LED codes for the CPU/Memory+ and I/O+ boards.

Table 9-2 LED Codes for the CPU/Memory+ and I/O+ Boards

Power	Service	Running	Condition
Off	Off	Off	Board has no electrical power.
Off	On	Off	Board is in low power mode, can be unplugged.
Off	Off	On	Undefined.
Off	On	On	Undefined.
On	Off	Off	System is hung, either in POST/OpenBoot or in the operating system.
On	Off	On	Hung in OS.
On	On	Off	(1) Hung in POST/OBP or (2) hung in OS and failed component on board.
On	On	On	(1) Hung in POST/OBP or (2) hung in OS and failed component on board.
On	Off	Flash	OS running.
On	On	Flash	OS running and failed component on board.
On	Flash	Off	Slow flash = POST. Fast flash = OBP.
On	Flash	On	Undefined.

The general rules for the CPU/Memory+ and I/O+ boards are:

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

• If the green LEDs (Power and Running) are not lit, the board is ready for removal.

• If no LEDs are flashing, the system is hung.

• The board requires service if the yellow Service LED is lit continuously (not flashing). Note that it is a normal condition for the Service LED to flash during POST testing.