Lenovo ThinkPad 365E-ED ThinkPad 365, SelectaDock I - Hardware Maintenance Man - Page 287

4. If the voltage is more than +11.0 V dc, measure the resistance between battery terminals 3 and 4. The resistance must be 4 to 30 K ohm. If the resistance is not correct, replace the battery pack. If the resistance is correct, replace the system board. Checking the Backup Battery 1. Power off the computer and unplug the AC Adapter from the computer. 2. Turn the computer upside down. 3. Remove the DIMM cover and backup battery (see "1010 Backup Battery" on page 298). 4. Measure the voltage of the backup battery. See the following figure. Note: Be careful not to measure the wrong side of the backup battery. Black (-) Red (+) + SONY Wire Red Black Voltage (V dc) +2.5 to +3.7 Ground If the voltage is correct, replace the system board. If the voltage is not correct, the backup battery has been discharged. Replace the backup battery. If the backup battery discharges quickly after replacement, replace the system board. Port Replicator Checkout Use the following procedure to isolate a port replicator problem. A port replicator attaches to the system expansion connector at the bottom of the computer. 1. Power off the computer. 2. Remove the failing devices from the replicator. 3. Unplug the AC adapter from the replicator, if attached. 4. Remove the port replicator from the computer. ThinkPad 560 (2640) 275