IBM 201 Light-path diagnostics, Diagnostics panel LEDs, Sp Fan, NAS 200 User’s Reference

Light-path diagnostics

You can use the light-path diagnostics built into the NAS 200 engine to identify the type of system error that occurred. Any LEDs that are illuminated remain illuminated during a shutdown as long as the AC power source is good and the power supplies can supply +5V DC current to the NAS 200 engine. This feature helps you isolate the problem, if an error causes the NAS 200 to shut down. See “Light-path diagnostics”.

Diagnostics panel

You can use the light path diagnostics to quickly identify the type of system error that occurred. The diagnostics panel is under the “wind tunnel”. Any LEDs that are On, remain On when the NAS 200 shuts down as long as the AC power source is stable and the power supplies can provide +5V DC current. This feature helps isolate the problem if an error causes the NAS 200 to shut down.

Figure 1 shows the LEDs on the diagnostics panel on the system board. You need to remove the top cover to view the LEDs.

See “Light-path diagnostics” for information on identifying problems using these LEDs.

MEM PS1

CPU PS2

PCI A PS3

PCI B NON

PCI C OVER

VRM NMI

DASD TEMP

SP FAN

REMIND

Figure 1. Diagnostics panel LEDs

Light-path diagnostics

Table 4 on page 51 describes the light-path diagnostics LEDs. The system error LED is turned on when an error is detected. If the system error LED (an amber “!” on the lower right corner) is on, remove the cover and check the diagnostic panel LEDs. Table 4 on page 51 is valid only when the system error LED is on.

Notes:

1.If a diagnostic panel LED is on and the information LED panel system error LED is off, there is probably an LED problem. Run LED diagnostics.

2.Check the System Error Log for additional information before replacing a FRU.

3.The DIMM error LEDs, processor error LEDs, and VRM error LEDs turn off when the system is powered off.

50NAS 200 User’s Reference