Acer Extensa 7620 TravelMate 7720 / 7320 and Extensa 7620 Service Guide - Page 117

K External keyboard If any of these devices do not work, reconnect the cable connector and repeat the failing operation. Memory check Memory errors might stop system operations, show error messages on the screen, or hang the system. 1. Boot from the diagnostics diskette and start the diagnostic program (please refer to main board. 2. Go to the diagnostic memory in the test items. 3. Press F2 in the test items. 4. Follow the instructions in the message window. NOTE: Make sure that the DIMM is fully installed into the connector. A loose connection can cause an error. Power System Check To verify the symptom of the problem, power on the computer using each of the following power sources: 1. Remove the battery pack. 2. Connect the power adapter and check that power is supplied. 3. Disconnect the power adapter and install the charged battery pack; then check that power is supplied by the battery pack. If you suspect a power problem, see the appropriate power supply check in the following list: K "Check the Power Adapter" on page 108 K "Check the Battery Pack" on page 109 Chapter 4 107