Mouse Troubleshooting

Most problems with mice are related either to its port connection, the mouse driver, the trackball in a trackball mouse or a trackball unit, and the operation of the mouse buttons.

In newer systems, the mouse is typically connected to the USB port or the dedicated PS/2 mouse port on the back of the unit. In ATX systems, the keyboard and mouse have been given the same six-pin mini-DIN connector and, unfortunately, they do not work interchangeably. Although plugging the mouse into the keyboard connector should not cause any physical damage, it does cause problems with getting the system to work. These connections tend to be color-coded so you can check to ensure the mouse is connected to the green connector.

For PnP-compatible mice, installation and configuration has become a fairly routine process. Connect the mouse to the PS/2 mouse port and let the system autodetect it and install the basic Windows mouse drivers.

However, specialty mice—including USB-connected mice, wireless mice, and infrared mice—along with other pointing devices might require special drivers that are supplied by the manufacturer and loaded from the disk or disc that accompanies the device. Older serial mice used one of the PC's serial ports as their interface. These ports had to be properly configured for the serial mouse to work properly.

When a trackball mouse is moved across the table, the trackball picks up dirt or lint, which can hinder the movement of the trackball, typically evident by the cursor periodically freezing and jumping onscreen. On most mice, you can remove the trackball from the mouse by a latching mechanism on its bottom. Twisting the latch counterclockwise enables you to remove the trackball. Then, you can clean dirt out of the mouse.

The other mechanical part of the mouse is its buttons. These items can wear out under normal use. When they do, the mouse should simply be replaced. However, before doing so, check the Properties of the mouse in the operating system to ensure that the button functions have not been altered. It would be a shame to throw away a perfectly good mouse because it had been set up for left-hand use in the operating system.

Mouse Hardware Checks

The hardware check for the mouse involves isolating it from its host port. Simply replace the mouse to test its electronics. If the replacement mouse works, the original mouse is probably defective. If its electronics are not working properly, few options are available for actually servicing a mouse. It might need a cleaning, or a new trackball. However, the low cost of a typical mouse generally makes it a throwaway item if simple cleaning does not fix it.

If the new mouse does not work either, chances are good that the mouse's electronics are working properly. In this case, the mouse driver or the port hardware must be the cause of the problem. If the driver is correct for the mouse, the port hardware and CMOS configuration must be checked.

The system board typically contains all of the port hardware electronics and support so it must be replaced to restore the port/mouse operation at that port. However, if the system board mouse port is defective, another option is to install a mouse that uses a different type of port (for example, use a USB mouse to replace the PS/2 mouse).

Mouse Configuration Checks

When a mouse does not work in a Windows system, restart it and move into safe mode by pressing the F5 function key while the "Starting Windows" message is displayed. This starts the operating system with the most basic mouse driver available. If the mouse does not operate in safe mode, you must check the mouse hardware and the port to which the mouse is connected.

If the mouse works in safe mode, the problem exists with the driver you are trying to use with it. It might be corrupt or it could be having a conflict with some other driver. To check the driver, consult Device Manager. If Device Manager shows a conflict with the mouse, remove the driver and allow the system's PnP process to reinstall it.

If the correct driver for the installed mouse is not available, you must install one from the manufacturer. This typically involves placing the manufacturer's driver disk or disc in the appropriate drive and loading the driver using the Update Driver (requires disk from original equipment manufacturer [OEM]) option on the Device Manager Mouse Properties page. If the OEM driver fails to operate the mouse in Windows, you should contact the mouse manufacturer for an updated Windows driver.

Tips to follow for troubleshooting

• Verify that there is no mouse movement at all. If your computer mouse has stopped moving completely, check the obvious. Make sure the computer mouse is plugged in completely. If it is, remove the plug and examine for pins that may be damaged.
• See that the mouse stops while you're using it. If the mouse is working perfectly and suddenly stops, check the connection to see if it is loose. If the connection is fine, open up the trackball and check for any fuzz or residue trapped in the trackball chamber. Remove any residue with a cotton swab and alcohol. Remove the trackball and clean it with the cotton swab and alcohol as well.
• Observe that the pointer is not working correctly. If the computer mouse pointer is working in an odd way, check for a virus. Some computer viruses cause the mouse to not work properly. Download a free anti-virus program at Free-AV to run a virus scan on the computer.
• Check the computer mouse driver. Go to "Control Panel" and open the "System" folder. Choose "Device Driver Tab" and arrow down to "Mouse." Look and see if the driver is installed. If there is a yellow icon, the mouse has a problem. Un-install the mouse and reboot the computer. Reinstall the mouse driver and reboot the computer.