IBM 8688 manual Check room temperature, Reseat DIMMs, re-enable DIMMs, if necessary, using

Service Processor message	FRU/action
System shutoff due to high ambient temperature	1.	Check room temperature.
	2.	Check for airflow obstructions.
	3.	Check fans.
	4.	Light Path assembly.
Xcel4 Accelerator Cache Error Detected.	Processor board
Uncorrectable memory error on DIMMs x, y	1.	Reseat DIMMs, re-enable DIMMs, if necessary, using the
		Configuration/Setup Utility program, and run diagnostics.
	2.	DIMMs x, y.
VRM 1-4 Fault	1.	Check microprocessor 1-4 power module cable.
	2.	Microprocessor 1-4 power module.
+2.5v VRM power fault	1.	Memory board 2.5v VRM
	2.	Memory board
+1.8v VRM power fault	1.	Memory board 1.8v VRM
	2.	Memory board
1.8v Fault	1.	Processor-board 1.8v VRM
	2.	Processor-board assembly
1.25v Fault	Processor board
Memory +1.8v Power fault	1.	Memory board 1.8v VRM
	2.	Memory board
Memory +1.25v Power fault	1.	Memory board 1.25v VRM
	2.	Memory board
Primary I/O Power fault	I/O board
Environmental Monitor Flash Update Failed.	1.	Retry Flash Update.
	2.	I/O board.
Environmental Monitor ROM error.	1.	Remove ac power for 20 seconds, reconnect, and run
		diagnostics.
	2.	Flash update system-management firmware.
	3.	I/O board.
Environmental Monitor RAM error	1.	Remove ac power for 20 seconds, reconnect, and run
		diagnostics.
	2.	I/O board.
Environmental Monitor firmware needs updating.	Flash update system-management firmware.
No environmental information currently
available.

The service processor also generates a large number of information, error, and warning messages.

If an RXE-100 unit is attached, the service processor might generate further messages specific to this unit. For information about these error messages, see “RXE port error codes” on page 173.

158IBM xSeries 450 Type 8688: Hardware Maintenance Manual and Troubleshooting Guide