On the Display you will have "[3] Bend Mod  ??? ???"
(where ??? is the Hex value of the bender and mod)
Push the bender lever left fully and gradually return it to the original position.
Press the [LOWER] button.
Push the bender lever rightward fully and then gradually return it to the original position.
Press the [UPPER] button.
Push the bender lever to the MOD position and then gradually return it to the original position.
Press the [KEY MODE] button
Then an '*' appears press the [UP] button then the '*' changes to a '<->' mark

Moving the bender you should get these readings, left -256 center 0 right 255
Moving the bender into the MOD position it should go up to 127 and then return to 0.
Now if the above things doesn?t happen, press the [3] button and readjust, if still not correct, take the keyboard to Roland service, as there could be a problem with either the bender unit itself, or some of the IC's could need to be replaced.