To enable USB Debugging and Developer options in Android 4.2 Jelly Bean devices, just follow as described below. – Open “Settings” and tap on About Phone. – Now, tap on Build number several times (at least 10 times) until you see a small popup with text “You are now a developer”.

That’s all! You have unlocked the USB debugging mode on Jelly Bean. Just go to Settings – Developer Options – Debugging – USB debugging whenever you want to enable/disable USB debugging option.