from your home screen on the phone, press this instead of your pin code "right", "*", "left", "left", "*", "left", "*"
see what happens
Access the engineering menu (type from the desktop >*<<*<* (do not consider what appears on the screen while typing)). In the shown menu choose "Service info" > "Model info". The model of target phone will be shown. And now type sequentially 2,4,6,8....
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