Lenovo System x3550 M5 Installation And Service Manual page 102

Power problems can be difficult to solve. For example, a short circuit can exist anywhere on any of the
power distribution buses. Usually, a short circuit will cause the power subsystem to shut down because of
an overcurrent condition. To diagnose a power problem, use the following general procedure:
Step 1. Turn off the server and disconnect all power cords.
Step 2. Check for loose cables in the power subsystem. Also check for short circuits, for example, if a
loose screw is causing a short circuit on a circuit board.
Step 3. Check for any errors indicated by the operator information panel or LCD operating panel assembly
(see "Operator information panel" on page 19 or "LCD operating panel assembly" on page 19 ).
Step 4. If the check log LED on the operator information panel is lit, check the IMM event log for faulty Pwr
rail and complete the following steps. Table 23 " Components associated with power rail errors"
on page 88 identifies the components that are associated with each Pwr rail and the order in
which to troubleshoot the components.
a. Disconnect the cables and power cords to all internal and external devices. Leave the
power-supply cords connected.
b. For Pwr rail 1 error, complete the following steps:
1. (Trained technician only) Replace the system board.
2. (Trained technician only) Replace the microprocessor.
c. For other rail errors (Pwr rail 1 error, see step 4b), remove each component that is associated
with the faulty Pwr rail, one at a time, in the sequence indicated in Table 23 " Components
associated with power rail errors" on page 88, restarting the server each time, until the cause
of the overcurrent condition is identified.
Table 23. Components associated with power rail errors
Pwr rail error in the IMM event log
Pwr rail 1 error
Pwr rail 2 error
Pwr rail 3 error
Pwr rail 4 error
Pwr rail 5 error
Pwr rail 6 error
Pwr rail 7 error
d. Replace the identified component.
Step 5. Remove the adapters and disconnect the cables and power cords to all internal and external
devices until the server is at the minimum configuration that is required for the server to start (see
"Power-supply LEDs" on page 60 for the minimum configuration).
Step 6. Reconnect all power cords and turn on the server. If the server starts successfully, reseat the
adapters and devices one at a time until the problem is isolated.
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Lenovo System x3550 M5 Installation and Service Guide
Components
• Microprocessor 1
• Microprocessor 2
• DIMMs 1 through 12
• Fan 3
• Fan 5
• Fan 6
• DIMMs 13 through 24
• Fan 7
• Fan 8
• SAS/SATA hard disk drives and USB
• Optional cable for VGA external power
• PCI-E and x16 (maximum expansion is 4 adapter cards)
• PCI-E hard disk drives
• Fan 1
• Fan 2