I updated my iMac's OS to Yosemite 10.10.5 and found that the Apple USB keyboard is no longer working.
I tried different USB ports to no result.
I tried using the keyboard on another computer and it works fine.
I tried an Apple Bluetooth keyboard and it works fine.
Would anyone know what I could do to get it working again?
Best Answer
Try this, while it is very basic: https://support.apple.com/kb/PH19094?locale=en_US Also check what other USB are working (mouse, etc.) Do a PRAM Reset Restart > Command + Option + P + R holding the keys when the Apple sign doesnt appear yet on the screen, it restarts and USB ports start working.
You can also try a SMC: https://support.apple.com/en-us/HT201295
I am using a new iMac with El capitan and preferred using my old USB keyboard instead of the elegant wirelerss one. No problems.