Solving Power Problems - Lenovo ThinkServer RD220 Hardware Maintenance Manual

Solving power problems

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:
1. Turn off the server and disconnect all power cords.
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.
3. If a power-channel error LED on the system board is lit, perform the following steps; otherwise, go to
step Solving power problems. SeeSystem-board LEDs for the location of the power-channel error LEDs.
Components associated with power-channel error LEDsTable 4 on page 124 identifies the components
associated with each power channel, 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. Remove each component that is associated with the LED, one at a time, in the sequence indicated in
Components associated with power-channel error LEDsTable 4 on page 124, restarting the server
each time, until the cause of the overcurrent condition is identified. Important: Only a trained
service technician should remove or replace a FRU, such as a microprocessor or the system board.
See Parts listing, ThinkServer RD220 Type 3729, 3779, 3797, and 3798 to determine whether a
component is a FRU.
Table 4. Components associated with power-channel error LEDs
Power-channel
error LED
A
B
C
D
E
240 V AUX
c. Replace the identified component.
4. 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 Features
and technologies for the minimum configuration).
5. Reconnect all power cords and turn on the server. If the server starts successfully, replace the adapters
and devices one at a time until the problem is isolated.
If the server does not start from the minimum configuration, replace the components in the minimum
configuration one at a time until the problem is isolated.
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ThinkServer RD220 Hardware Maintenance Manual
Components
CD/DVD drive (optical drive), fans, hard disk drives, hard disk drive backplanes
PCI riser-card assembly in PCI connector 1 on the system board, DIMMs 1 through 16,
microprocessor 2
Tape drive if one is installed, SAS riser card assembly, DIMMs 1 through 8,
microprocessor 1
Microprocessor 1, system board
Optional PCI video graphics adapter power cable if one is installed (connector J154 on
the system board), optional PCI video graphics adapter if one is installed, PCI riser card
assembly in PCI connector 2 on the system board, microprocessor 2
All PCI adapters and PCI riser-card assemblies, SAS riser card assembly, operator
information panel assembly, optional two-port Ethernet card if installed