IMac Intel Core Duo Keyboard Stops Working Intermittently

Question

Hello,
About every 10 minutes or so, maybe longer, my iMac's keyboard stops working completely. The list shown below are additional items that I have tried or is a side-effect to the keyboard issue:
The problem occurs on more than one keyboard, therefore, it doesn't seem to be a faulty keyboard issue
The quick solution is to unplug the keyboard from the back of my iMac and plug it in again. Then the keyboard resumes its normal operation. However, on some occasions, the unplug/plugin technique does not work. It that case, I have to do a hard power-down, wait 10 seconds, then turn the iMac on again. Normal keyboard operation is finally returned.
The mouse will turn off, which is indicated by the light inside the mouse turning off
If the mouse does turn off, I unplug it from the keyboard and plug it directly into the back of the iMac. The light inside the mouse comes back on, but the mouse cursor is unresponsive
The iMac Intel Dual Core is about six years old.
Any information is appreciated
Thank you,
Tony

Answer 1

Try doing a SMC reset, if that doesn't work try a PRAM reset. Don't be afraid to do these resets 2-3 times each if they don't work the first time.
_SMC RESET_
• Shut down the computer.
• Unplug the computer's power cord and all peripherals.
• Press and hold the power button for 5 seconds.
• Release the power button.
• Attach the computers power cable.
• Press the power button to turn on the computer.
_PRAM RESET_
• Shut down the computer.
• Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
• Turn on the computer.
• Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
• Hold the keys down until the computer restarts and you hear the startup sound for the second time.
• Release the keys.
Roger