Lenovo ThinkPad 360, Hardware Maintenance Manual

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Undetermined Problems
You are here because the diagnostic tests did not identify
which adapter or device failed, installed devices are
incorrect, a short circuit is suspected, or the system is
inoperative. Follow the procedures below to isolate the
failing FRU (do not isolate non-defective FRUs).
Verify that all attached devices are supported by the
computers.
Verify that the power supply being used at the time of the
failure is operating correctly. (See “Power Systems
Checkout” on page 322.)
1. Power-off the computer.
2. Check the cables, wires, and connectors for short
circuits and open circuits. Visually check them for
damage. If any problems are found, replace the
FRU.
3. Remove or disconnect all of the following devices.
a. Non-IBM devices
b. Devices attached to the expansion bus
connector
c. Printer, mouse, and other external devices
d. Battery pack
e. Hard disk drive
f. Diskette drive or the device attached to the
diskette drive connector
g. IC DRAM card or DIMM card
h. PC Cards
Note: Remember that removing the hard disk
drive, an IC DRAM card, or any adapter or
device, might cause configuration errors. Ignore
error code 174.
4. Power-on the computer.
5. Determine if the problem has changed.
6. If the problem does not occur again, reconnect the
removed devices one at a time until you find the
failing FRU.
7. If the problem remains, replace the following FRUs
one at a time. Do not replace a non-defective FRU.
Ÿ
DC/DC card
Ÿ
Interposer card
Ÿ
LCD assembly
Ÿ
System board
Ÿ
Processor card
ThinkPad 755CD, 755CDV (9545)
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