IBM B50 manual Bootlist, Scsi Device Errors Scsi device error notes

Error Code	Function	Repair Action/Possible Failing FRU
	/Description
20EE000A	Pointer to the	Values normally found in nonvolatile storage that point
	operating system	to the location of an Operating System were not found.
	not found in non	This can happen for either of two reasons:
	volatile storage.	Your installed Operating System does not support
		storing the values.
		Some event occurred that caused the system to
		lose nonvolatile storage information (drainage or
		replacement of the battery).
		If you are running AIX, this information can be
		reconstructed by running thebootlist	command
		specifying the device that the Operating System is
		installed on. Please refer to your AIX documentation
		for the exact syntax and usage of the	bootlist
		command.
		To boot the Operating System so that these values
		can be reconstructed, power down the system and
		power it back up again. This should cause the system
		to look for the Operating System in the devices
		contained in the custom boot list or in the default boot
		list, depending on the condition of the system. If this is
		not successful, use the System Management Services
		Menus to modify the Boot Sequence (also known as
		boot list) to include devices that are known to contain a
		copy of the Operating System. For example, select a
		hard disk known to have a copy of the Operating
		System as the first and only device in the boot
		sequence (boot list) and attempt to boot again.
20EE000B	The system was not	Modify the Boot Sequence (also known as boot list) to
	able to find an	include devices that are known to contain a copy of the
	Operating System	Operating System. This can be accomplished by
	on the boot list that	powering down the system, powering it back up again,
	was attempted.	and using the System Management Services Menus.
		For example, select a hard disk known to have a copy
		of the Operating System as the first and only device in
		the boot sequence (boot list) and attempt to boot
		again.
21A00xxx	SCSI Device Errors	SCSI device error notes:
		1. Before replacing any system components:
		a. Ensure that the controller and each device on
		the SCSI bus is assigned a unique SCSI ID.
		b. Ensure SCSI bus is properly terminated.
		c. Ensure SCSI signal and power cables are
		securely connected and not damaged.
		2. The location code information is required to identify
		the ID of SCSI device failures, as well as to
		indicate the location of the controller to which the
		device is attached.

3-47046 Model B50 Service Guide