One of the nice features of the Asus motherboards is that they often give you error messages specifying where a problem is coming from. This feature includes giving you an error message when there is a USB device or port issue. However, you can also determine if there is a USB problem simply by noticing that the ports do not function. Troubleshoot the problem to determine if it is a software issue or an electrical short of some type. If there is an electrical short, refrain from using that USB port or disconnect it from the motherboard if possible.
Driver Issues
USB issues can arise from faulty drivers. Go to "Start," "Control Panel" and "System and Maintenance." Click on the "Device Manager" link and look for a yellow precautionary triangle next to the USB driver. Download and install the latest USB driver for the ASUS M4A785TD-V EVO from the Asus website to get rid of the conflict.
CMOS Reset
Resetting the CMOS battery can sometimes fix a USB port issue. Unplug the tower from any power source. Open the computer case and remove the round, watch-like CMOS battery that sits in the center of the motherboard. Remove the plastic pin cover from pins two and three, and place it over pins one and two. Press the computer's "Start" button and hold it in for 10 seconds. Change the pin cover back to its original place. Replace the battery and the power cord. Start the computer to see if the error message is gone.
USB Devices and Ports
A USB short can be caused by a USB keyboard, mouse, speakers or other devices. It can also be caused by the port itself. Find out whether it is the external device that is causing the problem, or whether a port is causing the damage. Remove all of the USB devices. Connect and test the computer after attaching each device. Locate the device or port causing the problem by connecting the device causing the error into another USB port. Check to see if it causes the same error message when connected to another port. Open the case and inspect the USB port areas for foreign objects like loose screws, wires or cables that can be causing a short. Remove these objects and the port should work fine.
USB Header Cables
Front USB ports tend to fail faster than rear ports. Disconnect the front USB header cables from the motherboard by first opening the case and locating the cables toward the right front corner of the motherboard. These are pin-type connectors that you can simply pull off. Turn on the machine to check for the USB short message again. If it does not appear, leave the cables disconnected and only use the rear USB ports. You can always add a USB hub if you need more USB ports.
Tags: error message, another port, causing problem, CMOS battery, device port