Checking the ac power adapter You are here because the computer fails only when the ac power adapter is used. • If the power problem occurs only when the docking station or the port replicator is used, replace the docking station or the port replicator. • If the system status indicator does not blink three times when an ac power source is connected, check the power cord of the ac power adapter for correct continuity and installation. • If the computer does not charge during operation, go to “Checking the removable battery and the operational charging” on page 29. Note: Noise from the ac power adapter does not always indicate a defect. Checking the USB-C type ac power adapter To check the USB-C type ac power adapter, do the following: 1. Connect the computer to a power outlet and turn on the computer. 2. Start Lenovo Companion program, and then click Hardware Settings ➙ Power. The ac power adapter information is displayed. Ensure that you use the USB-C type ac power adapter that is shipped with the computer to provide enough power to the computer. Otherwise, a message will be displayed, prompting you that the computer will not be charged or will be charged slowly. Checking the removable battery and the operational charging Checking the removable battery This system supports only batteries specially designed for this specific system and manufactured by Lenovo or an authorized builder. The system does not support unauthorized batteries or batteries designed for other systems. If an unauthorized battery or a battery designed for another systems is installed, the system will not charge. Attention: Lenovo has no responsibility for the performance or safety of unauthorized batteries, and provides no warranties for failures or damage arising out of their use. Move your pointer to the battery-status icon in the Windows® notification area to check the battery status. The battery-status icon displays the percentage of battery power remaining and how long you can use your computer before you must charge the battery. Note: If the removable battery becomes hot, it may not be able to charge. Remove it from the computer and leave it at room temperature for a while. After it cools down, reinstall and recharge it. To check the removable battery, do the following: 1. Turn off the computer. 2. Remove the removable battery and measure the voltage between battery terminals 1 (+) and 7 (-). See the following figure: Chapter 3. General checkout 29