This one worked for me too , but I wasn't trying to do this exatcly . I had the JVM 513 error. Continuous Loop. Nuked BB. Needed the OS. I loaded the Mac desktop manager. It couldn't connect to the phone. Started writing emails while still connected with the USB and DM running, and presto, connected on its own ( the 20-25 tries must have happened) I saw icons of laptop connected to the phone and DM downloaded the OS. Then the DM loaded the operating system and waited for the phone to restart. Whole process took an hour or more. I was tempted often to unplug it but resisted. Paid off. Thanks.