iMac (Slot Loading): Computer Stops Responding at Startup with Multiple USB Devices

In some cases, the iMac (Slot Loading) does not respond when starting up. This typically occurs when two USB peripherals are connected and turned on. The USB drivers may not be installed, or may be installed but disabled through the Extensions Manager. The symptom does not occur if one of the peripherals is disconnected.
This intermittent issue has been verified with the Epson Stylus printer and an Iomega Zip drive or Imation SuperDisk drive, though it can occur with other USB peripherals in combination with the Epson Stylus printer.

The issue is related to the USB software in Mac OS 8.6 and has been resolved in Mac OS 9.

As a workaround, you may disconnect the peripheral that is not in immediate need. Since a USB device can be plugged in while the computer is running, disconnect one of the peripherals during system startup and reconnect it after the computer has successfully started.

Although this specific issue is not related to the driver version for the USB device, always make sure you are using the most current drivers.

Published Date: Feb 20, 2012