Here is what Java error 102 means:
The system has checked the .COD files in the handheld for modification, and determined that there is a problem with one or more .COD files.
If all loads fail, it could indicate a build process error where there was a problem signing the codfiles.
If some user action to the device caused this problem, the reset cycle will be continuous since the code in the filesystem has been corrupted. The only recovery method is to wipe the device and restore a new system.
With the information you have provided, I think you need to completely wipe the device and reload the operating system. Download JL_Cmder (link in my signature) and use option #5 to wipe the device. Dont worry about the Desktop Manager not being able to see the BlackBerry after being wiped, this is normal. Then you need to download and install the operating system. See the BlackBerryOS Upgrade
thread for OS download links and install instructions.