On an ASUS M4A motherboard is a built-in network interface controller that enables the computer to connect to the Internet. Attached to the NIC is an Ethernet port. Modems and routers can connect to this port, providing network access to the PC as a result. Problems with the NIC or its settings, however, can prevent the ASUS M4A from connecting to the Internet.
Hardware Setup
The ASUS M4A features a simple program, called the BIOS Setup Utility, that enables users to change the computer's hardware parameters. These parameters are stored to a non-volatile random access memory chip, called the complementary metal-oxide semiconductor. The basic input/output system, a low-level software that controls the ASUS M4A and its hardware, configures the system based upon the parameters stored in the CMOS. On the Onboard Devices Configuration screen, accessible from the Advanced tab, is an option called Onboard LAN Controller. If the option is disabled, the Ethernet port will stop working. Re-enable the option to restore function to the NIC.
Software Setup
Microsoft Windows also controls how the NIC behaves. Network Connections, accessible from the Control Panel, provides options to reconfigure the NIC or turn the component on or off. Windows assigns the label Local Area Connection to the NIC. If the icon associated with Local Area Connection is grayed out, the network adapter is turned off. Select the device, then click "Enable This Network Device" to turn the adapter on. Right-click the "Local Area Connection," and then click "Properties." Confirm that "Internet Protocol Version 4 (TCP/IPv4)" is checked. If this option is left unselected, the computer won't connect to websites.
Device Drivers
Device drivers, or software drivers, link together the ASUS M4A and its connected hardware. Drivers serve as a communication channel between the OS and the hardware; the OS sends data to the driver, which the driver then transfers to the hardware. The hardware performs a specific task based on the data it receives. If the device driver for the NIC is not working, the OS won't recognize the adapter and the Ethernet port won't work. You can check the status of the device driver in Device Manager, accesible from the Control Panel. If the Device Status field shows a message other than "This Device Is Working Properly," search for the error at Microsoft Support to find a fix for the problem.
Defective Hardware
Problems with the NIC itself can occur if the part of the board that contains the component is damaged. Electrostatic discharge, a form of static electricity that people sometimes produce when working on carpeted areas, can damage sections of the motherboard. If you recently handled the motherboard without first grounding yourself, you may have inadvertantly harmed the board with ESD, rendering the NIC - and its connected Ethernet port - nonfunctional. Motherboards can also come with manufacturing defects that cause components to wear out early. If you suspect that the motherboard itself is defective, you can install a replacement NIC to one of the expansion ports on the board. Disable the onboard LAN so that the new NIC doesn't interfere with the integrated one.
Tags: Ethernet port, Area Connection, Local Area, Local Area Connection, accessible from