Input malfunctions and how to avoid them

Problems with Apple's input devices are few but irritating. Some users have reported a lack of key input especially after waking computers from sleep, and sometimes specific keys not working. In addition, mice will sometimes become erratic and choppy. These problems can be related to a variety of issues depending on the specific user's setup.

Whenever users experience problems with input devices, we recommend that they first run through a few general troubleshooting steps to figure out where the problem lies. In addition to the general troubleshooting steps, there are some measures users can take to correct unique problems experienced with both keyboards and mice.

General Troubleshooting

Try the device in a new account User-specific settings might be contributing to the problem, in which case creating a fresh account in which to test the problem is a recommended first step. In the system preferences create a new user account and log into it. Then test the faulty devices, and if the problem has cleared then users can check their account-specific device settings, or check their home library for any problematic preference files or plug-ins that might have contributed to the problem. If users cannot figure the problem out, then at the very worst they can migrate to a new account.

Try the device in safe mode In addition to creating a new account, users can force Mac OS X to load only essential drivers by holding the shift key at boot to get into "Safe Mode". This will limit functionality such as internet connectivity, but if the problem clears then users can troubleshoot items they may have installed in the system folder.

Update the driver software to the latest versions Apple constantly releases updates and security patches to Mac OS X, and there is always potential for some small incompatibility to materialize. Third-party keyboard and mouse manufacturers keep up with these changes in their driver releases, so users should be sure to update. Apple has in the past released driver and firmware updates for the aluminum keyboards, so users should ensure their aluminum keyboards are updated to the latest version (currently version 1.2). In addition to updating the drivers, if the problem only occurs in a specific application then users might check for updates to that application or reinstall that app, and remove application-specific preference files.

Keyboard Problems

Keyboard not functional upon waking from sleep In some cases a driver issue can occur in which, upon waking from sleep, the driver is not properly initiated to communicate with the keyboard. As such, while users can most likely get the keyboard working again by unplugging it and plugging it back in, users might also try to run a permissions repair on the drive and reset the computer's PRAM. If the driver is a third-party driver, then updating or reinstalling it may help.

Specific keys not working Sometimes dirt and grime can get in a key and prevent it from working. In most keyboards the keys can be removed by popping them off and then cleaning out the button and hinge mechanisms with a compressed air duster or Q-tip. The aluminum keyboards are slightly different because of their low profile, and as such users must be sure to take the keys off in a specific manner. At the top and bottom of the key there are hinges, but only the top snaps on and off. As such, to remove a key on the keyboard, insert a thin but sturdy object like a fingernail under the top edge of the key and slightly depress the bottom of the key to ensure that part stays down. Then pry the top out until the key pulls off, and it should snap out so users can clean the mechanism.

Keys generate error tones or perform unexpected functions Some users have had bizarre problems where the keys seem to be communicating with the computer, but instead of creating letter inputs it spurs an alert sound or perform some bizarre function. In this case there is probably some system setting that's been inadvertently assigned to the key, such as the option to speak selected text, or listed for speech recognition. As such, users can check system settings or settings of third-party enhancement software to see if the key is being reserved for another function. Recommendations include the "Speech" system preferences and the "Keyboard & Mouse" preferences, as well as the settings for alternate mouse drivers.

Mouse Problems

Jumpy and Erratic behavior This is a relatively common problem, especially with wireless mice. The first thing to do is check the battery level for the device, as low batteries can create problems. Secondly users can try the mouse on a different surface to ensure there is no tracking problem. Additionally, be sure there is no interference with the mouse, by moving items out of the way and potentially resetting the mouse and having the computer rediscover the connection.

Sudden Freezing MacFixIt reported on some methods to fix this problem, which is another issue users have experienced with mice in OS X. Users can try updating software, as well as resetting the computer's PRAM, but in addition users have found that reducing the mouse speed can also reduce the prevalence of this issue.

If after troubleshooting users have found their keyboard or mouse is not functioning and needs to be replaced, users can temporarily use any USB keyboard or mouse to control their computers. In addition, users can control their computers through Mac OS X's "Screen Sharing" function until they replace the keyboard.

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