IBM 866631Y - Netfinity 7100 - 8666, Hardware Maintenance Manual

Page: 29 / 198

Table 1. Light path diagnostics (continued)
LED Cause Action
FAN One of the fan assemblies has
failed or is operating too
slowly.
Note:
A failing fan can also
cause the TEMP and DASD
LEDs to be on.
The LED on the failing fan assembly will be
lit. Replace the fan assembly.
TEMP The system temperature has
exceeded the maximum rating. 1. Check to see if a fan has failed. If it has,
replace the fan.
2.
Make sure the room temperature is not
too high. (See “Temperature checkout” on
page 20.)
If the problem persists, see “Diagnostic panel
LEDs” on page 122.
NON RED Server drawing too much
power to operate in a
redundant power mode. System can continue to operate in a
nonredundant power mode. To operate in a
redundant mode, add a power supply or
remove most recently installed options.
OVER
SPEC The server is drawing more
power than the power
supplies are rated for. Either add a power supply or remove a
device from the server.
PS1 The first power supply has
failed. Replace the first power supply.
PS2 The second power supply has
failed. Replace the second power supply.
PS3 The third power supply has
failed. Replace the third power supply.
PS4 The fourth power supply has
failed. Replace the fourth power supply.
Power checkout
Power problems can be difficult to troubleshoot. For instance, a short circuit can
exist anywhere on any of the power distribution busses. Usually a short circuit will
cause the power subsystem to shut down because of an overcurrent condition.
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
instance 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 system is at minimum configuration
required for power on (see
″
Minimum operating requirements
″
on page 131).
4. Reconnect the AC cord and power on the system. If the system powers up
successfully, replace adapters and devices one at a time until the problem is
isolated. If system does not power up from minimal configuration, replace
FRUs of minimal configuration one at a time until the problem is isolated.
To use this method it is important to know the minimum configuration required
for a system to power up (see page 131). For specific problems, see “Power error
messages” on page 139.
Diagnostics
19