Get the serial on the screen. Hold presets 1 and 6 together: the radio cycles through information on the display. On a Sony unit the serial begins SO or SN, and its last seven characters are a V followed by six digits — that is what unlocks the stereo. You can also type the whole S0CD… line from the label.
Entering the code. Sony units have a number keypad: just type the code — the cursor moves on by itself — and confirm by holding the * key, or OK on units without it.
Most units lock for good after about ten wrong attempts, so work from the serial, not from code lists.
Hold presets 1 and 6 together. The serial starts SO or SN; its last seven characters, a V and six digits, are what the code is worked out from.
Type it on the number keypad and confirm by holding the * key, or OK on units without it.