HP LJ475UT Testing an AC adapter

Testing an AC adapter

Test the AC adapter if the computer exhibits any of the following symptoms when it is connected to AC power:

●The computer does not turn on.

●The display does not turn on.

●The power light is off.

To test the AC adapter:

1.Shut down the computer.

2.Remove the battery from the computer.

3.Connect the AC adapter to the computer, and then plug it into an AC outlet.

4.Turn on the computer.

●If the power light turns on, the AC adapter is functioning properly.

●If the power light remains off, the AC adapter is not functioning and should be replaced. Contact technical support for information on obtaining a replacement AC power adapter.

Using external AC power 45

Contents

Page Page Safety warning notice Page Table of contents Page Page Page Page Page 1 Welcome Finding information 2 Getting to know your computer Top TouchPad Lights Buttons Keys Page Front Right Left Page Display Bottom 3 Networking Using an Internet service provider (ISP) Identifying wireless and network status icons Creating a wireless connection Turning wireless devices on and off Using a WLAN Connecting to an existing WLAN Setting up a new WLAN Protecting your WLAN Roaming to another network Using Bluetooth wireless devices (select models only) Connecting to a wired network Using a modem (select models only) Connecting a country- or region-specificmodem cable adapter Connecting to a local area network (LAN) (select models only) 4 Keyboard and pointing devices Using the keyboard Identifying the hotkeys Page Using keypads Using the integrated numeric keypad Using the TouchPad Turning the TouchPad off and on Navigating Selecting Using TouchPad gestures Setting pointing device preferences 5 Multimedia Using the media activity keys Using the audio features Adjusting the volume Checking your audio functions Using the Webcam (select models only) Using video devices VGA Connecting an HDMI device (select models only) Configuring audio for HDMI (select models only) 6 Power management Shutting down the computer Setting power options Using power-savingstates Using the Power icon Using power management Using battery power Displaying the remaining battery charge Inserting or removing the battery Charging a battery Maximizing battery life Managing low battery levels Conserving battery power Storing a battery Disposing of a used battery Replacing the battery Using external AC power Testing an AC adapter 7 Drives Handling drives Replacing or upgrading the hard drive Removing the hard drive Page Installing a hard drive Page Using optical drives (select models only) Identifying the installed optical drive Inserting an optical disc Removing an optical disc Page Page 8 External cards and devices Using Digital Media Slot cards (select models only) Inserting a digital card Removing a digital card Using ExpressCards (select models only) Configuring an ExpressCard Inserting an ExpressCard Removing an ExpressCard Using a USB device Connecting a USB device Removing a USB device Using optional external devices Using optional external drives 9 Memory modules Page Page Page Page 10 Security Protecting the computer Using passwords Setting passwords in the operating system Setting passwords in Computer Setup Managing an administrator password Entering an administrator password Managing a power-onpassword Using firewall software Installing an optional security cable 11 Backup and Recovery Performing a system recovery Backing up your information 12 Computer Setup Starting Computer Setup Using Computer Setup Navigating and selecting in Computer Setup Restoring factory settings in Computer Setup Updating the BIOS Determining the BIOS version Downloading a BIOS update A Troubleshooting and support Troubleshooting The computer is unable to start up The computer screen is blank Software is functioning abnormally The computer is on but not responding The computer is unusually warm An external device is not working The wireless network connection is not working The optical disc tray does not open for removal of a CD or DVD The computer does not detect the optical drive A disc does not play A movie is not visible on an external display The process of burning a disc does not begin, or it stops before completion Contacting customer support Labels B Cleaning your computer Cleaning products C Specifications Input power Operating environment D Electrostatic discharge Index