IBM 201 manual Power problems

Power problems

Power problems can be difficult to troubleshoot. For example, a short circuit can exist anywhere on any of the power distribution busses. Usually a short circuit causes the power subsystem to shut down because of an overcurrent condition.

Table 6 lists the power error messages that you might encounter.

A general procedure for troubleshooting power problems is as follows:

1.Power off the system and disconnect the AC cord(s).

2.Check for loose cables in the power subsystem. Also check for short circuits, for example, if there is a loose screw causing a short circuit on a circuit board.

3.Remove adapters and disconnect the cables and power connectors to all internal and external devices until the NAS 200 engine is at minimum configuration required for power on.

4.Reconnect the AC cord and power on the NAS 200 engine. If the engine powers up successfully, replace adapters and devices one at a time until the problem is isolated. If the engine does not power up from minimal configuration, replace FRUs of minimal configuration one at a time until the problem is isolated.

Table 6. Power error messages

Message	Action
Power supply ″X″ current share fault	1.	See “Power problems”
(level-critical; excessive current demand on
power supply ″X″)
Power supply ″X″ DC good fault	1. Replace power supply ″X″
(level-critical; power good signal not detected
for power supply ″X″)
Power supply ″X″ temperature fault	1.	Replace fan ″X″
Power supply ″X″ removed	1.	No action required - information only
Power supply ″X″ fan fault (level-critical;	1. Replace power supply ″X″
fan fault in power supply ″X″)
Power supply ″X″ 12V fault (level-critical;	1.	See “Power problems”
overcurrent condition detected)
Power supply ″X″ 3.3V fault (level-critical;	1.	See “Power problems”
3.3V power supply ″X″ had an error)
Power supply ″X″ 5V fault (level-critical; 5V	1.	See “Power problems”
power supply ″X″ had an error)
System over recommended ″X″ current	1.	See “Power problems”
(level-non-critical; system running too much
current on that voltage)
System running non-redundant power	1. Add another power supply
(level-non-critical; system does not have
	2. Remove options from system
redundant power)
	3. System can continue to operate without redundancy protection if 1
		and 2 above are not followed.
System under recommended voltage for	1. Check connections to power subsystem
″X″ v (level-warning; indicated voltage
	2.	Replace power supply
supply under nominal value; value for ″X″
	3.	Replace power backplane
can be +12, -12, or +5)

Chapter 7. Troubleshooting 57