IBM totalstorage 326, User Reference

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Light-path diagnostics
You can use the light-path diagnostics built into the Model 326 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 5V DC current to the Model 326 engine. This feature helps you isolate
the problem, if an error causes the Model 326 engine 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 Model 326 engine shuts down as long as the AC power
source is stable and the power supplies can p5V DC current. This feature
helps isolate the problem if an error causes the Model 326 engine to shut down.
Figure 2 shows the LEDs on the diagnostics panel on the system board. You must
remove the top cover to view the LEDs.
See “Light-path diagnostics” for information on identifying problems using these
LEDs.
Light-path diagnostics
Table 8 on page 89 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 8 on page 89 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.
MEM
CPU
PCI A
PCI B
PCI C
VRM
DASD
SP
PS1
PS2
PS3
NON
OVER
NMI
TEMP
FAN
REMIND
Figure 2. Diagnostics panel LEDs
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Model 326 User’s Reference