Hangtown Fry wrote:
The USB tree under System Information does not list it.
Until it does, no amount of printer driver installation, removal or reinstallation is going to help. The detection of the device on a USB bus is not printer driver dependent - it is something built in to the Mac.
With all the steps you have taken already, I wonder if there is something about the new iMac's and USB power? This is the second new iMac in this forum that is not detecting a Canon printer (a different model altogether and much newer than your model) on the USB port. I don't have access to a new iMac to test this theory. If you know someone that does have a small printer that they can bring over for testing, it will help with isolating the cause.
The problem appears to corrected now. I tried connecting a fourth USB cable and the computer recognized the printer and asked to download the software. Unfortunately the download failed due to corruption. A bit more searching the Mountain Lion/Printer Support Community and I found your 3 Dec. 2012 advice to LeeNixon regarding connecting a Canon MP500 and OS 10.8.2.
"Well you can trash the BJPrinters folder located in HD > Library > Printers > Canon."
"And then trash the Canon folder in HD > Library > Caches"
"And finally see if there is a Canon package in HD > Library > Receipts. If so, trash this."
"Then disconnect the MP500 USB cable from the Mac, restart the Mac and after you have logged back in, connect the USB cable again. If the device is detected by the Mac, it will attempt to download the driver from Apple. You can also open System Information to see if it is showing under one of the USB busses."
This worked and I am now able to print. I haven't tried scanning yet, but we'll see.