Chapter 4 742. 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 correctly inserted into the connector. A wrong connection will cause errors.Power System CheckTo verify the symptoms, power on the computer by using the following power sources separately.1. Remove the battery pack.2. Connect the power adaptor and check the power supply.3. Disconnect the power adaptor and install the battery pack, then check the power supply.If you think there is a power supply problem, please go to “Check the Power Adaptor” and “Check the BatteryPack” in this chapter.Check the Power AdaptorUnplug the power adaptor cable from the computer and measure the output voltage at the plug of the poweradaptor cable. See the illustration and follow the procedures below.1. If the voltage is not correct, replace the power adaptor.2. If the voltage is within the range:(1) Replace the system board.(2) If the problem is still not resolved, see “Undetermined Problems”.(3) If the voltage is not correct, go to the next step.Note: An audible noise from the power adaptor does not always indicate a defect.3. If the power-on indicator does not light up, check the power cord of the power adaptor for continuity and correctinstallation.4. If the operational charge does not work, see “Check the Battery Pack”.Check the Battery PackFollow the procedures below to check the battery pack.From software, this helps to identify the problem is on recharging or discharging.1. Check the Power Management in Control Panel.2. Then confirm that the parameters shown in the screen for Current Power Source and Total Battery PowerRemaining are correct.3. Repeat the step 1 and step 2 for both battery and adaptor.From hardware, this helps to identify whether you should replace the battery pack or not.1. Power off the system.2. Remove the battery pack and measure the voltage between terminals one (+) and seven (-). There are seventerminals totally. See the illustration below.3. If the voltage is still less than 7.5V after recharging, replace the battery.If the battery status indicator does not light up, remove the battery pack. After the battery pack returns to roomtemperature, reinstall it to the system.pin 1: +19V to +20.5Vpin 2: 0V, ground