I have a USB Keyboard connected to my 2012 MacBook Air running OS X 10.9.5. I use the computer in closed-lid mode and connected to a monitor. Often, but not always, when I wake the computer from sleep, I have to repeatedly tap keys on the keyboard before the keyboard starts responding. The sequence of events is as follows:
- I wake the computer from sleep by pressing a key on the keyboard.
- I attempt to type, and nothing happens. Not even the caps lock key on the keyboard works to illuminate the caps lock light.
- I rapidly press random keys (or a single key) on the keyboard, and the keyboard begins to respond after a while.
The USB keyboard is connected with a powered USB hub between the keyboard and the computer. Using a different hub does not solve the problem. The keyboard does still show up under USB devices in System Information when it is not responding.
Is there a solution to this annoyance?
UPDATE: When the keyboard is not responding, I can make the caps lock light on the keyboard illuminate by pressing the caps lock button with the mouse in the OS X keyboard viewer. Doing so does not restore the keyboard to a responsive state though. I still have to repeatedly tap keys before the keyboard starts responding.
UPDATE: The problem remains under OS X 10.11.6.
Best Answer
Since it’s intermittent, I would suspect a slow disk or just a lot of CPU and the bus is failing. Any chance you could move to an SSD for faster sleep wake or triage / isolate all other usb devices or check that device on another computer?