FRESH INSTALL OS AND RESTORE BACKUP
Follow steps below :
1. BACKUP all your data (Full BackUp) - IF YOU STILL ABLE TO ACCESS YOUR BLACKBERRY
2. Download BSAK : http://www.bbsak.org/
3. BlackBerry Desktop Manager 6 : https://www.blackberry.com/Downloads/entry.do?code=A8BAA56554F96369AB93E4F3BB068C22&CPID=OTC-SOFTWAREDOWNLOADS&cp=OTC-SOFTWAREDOWNLOADS
4. Download OS
Choose from Maxis, DiGi or Celcom
Choose Your Device (if you can't find, check below)
http://www.blackberryos.com/forums/downloads.php?do=cat&id=28 (You need to register first)
A. For WIPE and Reinstall OS.
1. Install BBSAK
2. Install Desktop Manager (if you haven't do so)
3. Connect your Device with BSAK via USB
4. In BSAK click on Wipe Device
5. After done, your device will restart and leave Error 507...
No worry, this Error means you need to reinstall OS
B. Reinstall OS
1. Install the *.exe files
2. Go to c:\program files\common files\research in motion\apploader and delete the file named "vendor.xml."
3. Plug in BB using USB and double click on "Loader.exe." It's located in the same place as the above vendor.xml file.
4. When you receive a confirmation message that the update is complete, you can disconnect your device.
C. Restore BackUp - IF YOU HAVE PREVIOUS ONE
1. Open BlackBerry Desktop Manager
2. Click Device
3. Choose Restore
4. Choose your BackUp