What to do next if Jl Cmder will not connect and wipe

• Note: If you are connecting via a USB HUB then these instructions may not work. Try connecting via USB on a PC that is not using a HUB

Pre-Install Tasks

1. Disconnect the device from the PC

2. Download and install Desktop Manager and the Handheld OS to the PC (if they have not already been installed):

 Desktop Manager and Handheld OS List

Command Line Tasks

1. Start a Command Prompt in DOS from the PC (Start >> All Programs >> Accessories >> Command Prompt)

2. Change the directory to: C:\Program Files\Common Files\Research In Motion\AppLoader

• If you do not know how to navigate to this directory follow instructions in 2a)

 2a)
 
 From C:\ prompt type: 
 
 cd \Program Files <hit enter>
 cd Common Files <hit enter>
 cd Research In Motion <hit enter>
 cd AppLoader <hit enter>

3. Make sure Desktop Manager is not running

4. Connect BlackBerry to the PC

5. Enter the following command in the Command Prompt window:

 loader.exe /nojvm

Installation

1. The Application Loader Wizard window will open

2. Click on Next

3. You will get a drop down list with the COM ports and one USB port entry

4. Select the one which says USB:UNKNOWN

• If you do not see USB:UNKNOWN or USB:BBPIN, then follow instructions listed in a1-a5:

 a1) Disconnect the device from the PC. 
 
 a2) Keep the Application Loader Wizard window open
 
 a3) Remove the battery and put it back
 
 a4) While the red led is on, reconnect the device to the PC. The led will only stay on for a few seconds
 
 a5) When USB:UNKNOWN appears in the drop down list, you need to immediately select Next

5. The loader should now connect to your device and you will be able to reinstall the OS
Thanks to acnst @ BlackBerry Forums