The code simply means, in practice, that the signal has been sent to the system - the operating system is still given time to shutdown the system (i.e. respond to the signal). Think of this as a short press on a PC Power button - how the system responds is dependent on OS settings and state. If you feel this is taking too long - normally mine shutdown within 3 minutes - then you can do an immediate shutdown. Think of the immediate shutdown as pressing, and holding, a PC power button until the system shuts off.

In other words - the LCD code does not guarantee that the partition will stop - it only indicates that a signal has been sent to the partition.

1) The code D200A200 is fairly 'normal'. It means AIX has been sent a rc.shutdown signal - in HMC terms: delayed shutdown, not operating system shutdown.

2) If the system "panic" stopped, and you have the system set to save dumps, there should be a file in /var/adm/ras named vmcore.X (X starts at zero, and increments for each core dump saved).

To check this setting use: lsattr -El sys0 -a fullcore
To check if system/partition auto restarts on a crash: lsattr -El sys0 -a autorestart

On my system - I do not not collect fullcore dumps, but I do restart: Note - I add the argument H for header information and requested both attributes. Skip the -a arguments for all attributes.
# lsattr -EHl sys0 -a fullcore -a autorestart  # Note added H to generate headers
attribute   value description                               user_settable

fullcore    false Enable full CORE dump                     True
autorestart true  Automatically REBOOT system after a crash True


p.s. AIX 5.2 is old, and ML09 is old within AIX 5.2. Check: AIX 5.2 Service Bulletins