Lenovo ThinkPad 380ED ThinkPad 380, 385, 560, 560E, all 760, 765 and SelectADo - Page 230

(-) (+) Red Black 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. Checking the Standby Battery 1. Power-off the computer and unplug the AC Adapter from the computer. 2. Open the keyboard, and remove the diskette drive/CD-ROM drive, the battery pack, and the hard disk drive. 3. Remove the top cover and keyboard unit. 4. Open the keyboard unit; then remove the keyboard card. 5. Remove the standby battery from the keyboard card. (Refer to "1200 Backup Battery, Speaker, Standby Battery" on page 288 to remove the battery.) Warning: Be careful not to cause a short circuit when measuring the voltage. 6. Measure the voltage of the standby battery. If the voltage between red and black is 3.5 V dc or greater, the voltage is correct. Go to step 12 on page 219 to verify standby battery operation. 218 IBM Mobile Systems HMM