Lenovo ThinkPad 370 Hardware Maintenance Manual - Page 217

8. If the drive is attached through a Diskette Drive Attachment Unit, replace the unit. Power Systems Checkout To verify the symptom of the problem, power-on the computer using each of the power sources available as follows. 1. Remove the battery pack, diskette drive, and hard disk drive. 2. Connect the AC Adapter and check that power is supplied. 3. Install the diskette drive, or hard disk drive one at a time and check that power is supplied from each power source. 4. Disconnect the AC Adapter, remove the hard disk and diskette drive, and install the charged battery pack; then check that power is supplied by battery pack. If you suspect a power problem, see the appropriate power supply check listed below. "Checking the AC Adapter." "Checking Operational Charging" on page 208. "Checking the Battery Pack" on page 208. "Checking the Car-Battery Adapter" on page 210. "Checking the Quick Charger" on page 211. "Checking the Backup Battery" on page 211. "Checking the Standby Battery" on page 212. "Port Replicator Power Overload" on page 215. Checking the AC Adapter: You are here because the computer fails only when the AC Adapter is used. If the power problem occurs only when the port replicator is used, replace the replicator. If the power-on indicator does not turn on, check the power cord of the AC Adapter for correct continuity and installation. If the operational charge does not work, go to "Checking Operational Charging" on page 208. Note: There are two types of adapters. The procedure for checking both types is the same. 1. Unplug the AC Adapter cable from the computer and measure the output voltage at the plug of the AC Adapter cable. See the following figure. 2 1 ThinkPad 355x, 360x, 370C, 750x, 755C, 755Cs 207