Recover files from Time Machine after a failed transfer to your new Mac
When transferring the data from your older Mac onto a new one using Migration Assistant, it is possible that all the files may not transfer correctly. If you have a Time Machine backup, all is not lost!
My client, Portland-based advertising agency, Mutt Industries welcomed a new employee to the fold and did some computer swapping. They needed to transfer files from an older MacBook Pro to a newer one after doing a clean install of Mac OS X 10.6.3 Snow Leopard (using a retail disc). Once Snow Leopard was installed on the newer MacBook Pro, we connected the older MacBook Pro via FireWire during the initial setup process to transfer the older information. The transfer seemed to go through without a hitch--all the information appeared to be in order and the newer MacBook Pro looked the same as the older one. We then did a clean install on the older MacBook Pro to prepare it for the new employee.
Two days later, I received a call saying that the original files had not been completely transferred from the older MacBook Pro to the newer one. Apparently the entirety of the Desktop folder was copied just fine (which is why it looked to have been a successful transfer), but the sub-folders within the user account did not make it. Fortunately they had used Time Machine (backed up to their internal server) to keep up-to-date backups.
Normally, one would be able to access their Time Machine backup and recover files that they needed from their machine's history. However, since the files needed to be recovered to a different machine, using the Time Machine application was not an option.
Though it may not be the most elegant solution, this workaround is effective in recovering your files. Simply navigate to Applications > Utilities and open Migration Assistant. Using Migration Assistant, you can restore from a Time Machine backup as a new user on your current machine. Once the new information has transferred, simply access the files you need from your new user, drag them to the system level of your machine, switch to your original user and drag them to your desired location on your hard drive. You may need to enter your administrator password in order to move some files. Remember, these files are copied, so be sure to trash the system level versions after placing them in your original files.