View Full Version : iMac won't wake unless firewire cable to ext drive is disconnected

Dec 26, 2008, 11:40 PM
Please advise....I have a 1TB Western Digital hard drive connected to a 24" 3.0GHz iMac via the Firewire 400 port. Frequently, the iMac will not wake up from being asleep unless the Firewire cable to the hard drive is disconnected. The hard drive is being used for Time Machine. Also, the iMac won't boot up after a restart unless the firewire is disconnected. I've had the iMac for over 6 months and finally started looking around for a solution.

Thanks in advance!

Sun Baked
Dec 26, 2008, 11:54 PM
If you have recently upgraded to 10.5.6

Resetting the SMC can resolve some computer issues such as not starting up, not displaying video, sleep issues, fan noise issues, and so forth. If your computer still exhibits these types of issues after you've restarted the computer, try resetting the SMC.

1. From the Apple menu, choose Shut Down (or if the computer is not responding, hold the power button until it turns off).
2. Unplug all cables from the computer, including the power cord and any display cables.
3. Wait at least 15 seconds.
4. Plug the power cord back in, making sure the power button is not being pressed at the time. Then reconnect your keyboard and mouse to the computer.
5. Press the power button on the back to start up your computer.

This should get rid of this error...

AppleFWOHCI_AsyncReceive::waitForDMA - context not going inactive.
AppleFWOHCI_AsyncTransmit::waitForDMA - context not going inactive.

That might be causing FW issues.

As far as Time Machine, switching to USB2 might help.