IBM DS3950, User And Installation Manual

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When you power on the storage expansion enclosures, the seven-segment LEDs
show 88 before the boot firmware starts to run. After the boot code starts, - - is
displayed.
When the application code starts, the ESMs display either aa or bb depending on
whether it is ESM A or B.
When the storage expansion enclosure is operating normally, the numeric display
shows the enclosure identification (enclosure ID) of the storage expansion
enclosure.
If an error has occurred and the Needs Attention LED is on, the numeric display
shows diagnostic information. The numeric display indicates the information is
diagnostic by illuminating an LED that appears as a decimal point between the
display numbers. The diagnostic LED turns off when the numeric display shows
the storage subsystem enclosure ID. The numeric display shows various diagnostic
codes as the enclosures perform the startup process after each power cycle or reset.
After diagnostics are complete, the current storage subsystem enclosure ID is
displayed.
Diagnostic codes in the form of Lx or Hx, where x is a hexadecimal digit, indicate
storage expansion enclosure state information. In general, these codes are
displayed only when the storage expansion enclosure is in a non-operational state.
The storage expansion enclosure might be non-operational due to a configuration
problem (such as mismatched types), or it might be non-operational due to
hardware faults. If the storage expansion enclosure is non-operational due to
system configuration, the storage expansion enclosure Needs Attention LED is off.
If the storage expansion enclosure is non-operational due to a hardware fault, the
storage expansion enclosure Needs Attention LED is on. The definitions for Lx
diagnostic codes are listed in Table 19 on page 56.
76041
Diagnostic LED
Seven-
segment
display
ds48042
Figure 32. Numeric display LEDs
Chapter 4. Operating the EXP395
55