Acer TravelMate 7720 TravelMate 7720 / 7320 and Extensa 7620 Service Guide - Page 118

Check the Power Adapter Unplug the power adapter cable from the computer and measure the output voltage at the plug of the power adapter cable. See the following figure Pin 1: +19 to +20.5V Pin 2: 0V, Ground 1. If the voltage is not correct, replace the power adapter. 2. If the voltage is within the range, do the following: K Replace the System board. K If the problem is not corrected, see "Undetermined Problems" on page 124. K If the voltage is not correct, go to the next step. NOTE: An audible noise from the power adapter does not always indicate a defect. 3. If the power-on indicator does not light up, check the power cord of the power adapter for correct continuity and installation. 4. If the operational charge does not work, see "Check the Battery Pack" on page 109. 108 Chapter 4