There are two types of models for Nexus 9. This should be noted.My model is a Nexus 9 with all the bells and whistles. While a clever person could use this guide, it would be nice to...
Answer to "My 6v adapter has interchangeable tips."Usually, the center is + There may be a label on it that shows a dot, mostly encircled with a line coming from the dot in the center. This line would be labeled with a + if my assumption is correct.