Ever since I bought the mid 2011 iMac running Lion, the problem occurred. While booting, a gray progressbar appears and when the device is finally booted, performance is really bad while no sound nor camera is available. And I’m not the only one, but I found that out only after searching quite some time and after the computer was sent to my service center…
How to reproduce
- The Bluetooth keyboard and mouse are switched off
- Switch on the Bluetooth keyboard. The led will light continuously, then starts flashing,
- Within two to three seconds, switch on the iMac
- The keyboard led will stop flashing and the iMac and keyboard are connected
- The progress bar appears
- When the device is booted, video performance is bad, in- and output sound devices are not found and camera cannot be started
- When the iMac is rebooted, everything works as smoothly as you expect from a Mac
Just leave your keyboard on, don’t switch it off when you shut down the iMac. It won’t use (a lot of) battery as long as you don’t use it. After one month, my battery level indication still displays 100%… Moreover, it’ll probably use more battery when you switch it off then on, because it’s going to search for other devices every time. When you don’t switch it off, it’ll stay paired with one device.
When you need to use some startup key combinations, the keyboard will act and connect before booting and the key sequence is processed. When you don’t need to enter such a sequence, the keyboard will connect right before the login screen appears. In both situations, the progress bar won’t appear.
Only when you’re not going to use the keyboard for a couple of days/weeks, you might want to switch it off. When you return from vacation and want to use your computer again, first switch on the iMac, wait for the grey Apple logo and spinner to appear, then switch on your keyboard and mouse. This is a work-around which in my opinion shouldn’t be necessary, but now that I know it and my solution will save me time (turning off the keyboard takes about three seconds every time, so that’s three seconds to do something else 😉 ), I can live with it.
How the keyboard works
It probably has something to do with the fact that when you shut down the keyboard, then switch it on again, it’ll be open to pair with another device. Probably the iMac has a problem with that. When you don’t switch the keyboard off and you shut down the iMac, the keyboard will go in some kind of power-efficient sleep mode. So this gives you the option to just keep the keyboard on. You’ll use rechargeable batteries anyway. When you’re still not sure and want to be the most energy-efficient, you’d better go with option two to start up the iMac, wait for the logo, then switch on the keyboard…