How Many Times Have You Used Your Slider?
I didn't know. So I started searching the Internet for an answer to this question. I didn't have to wait long as PreCentral.net forum member furreverdad posted a way to find the answer.
Open the Device Info application on your Pre and tap the More Info button at the bottom of the page. Once you do, tap the Preferences pull down menu, and select Interactive Tests. Run the Hardware buttons test. Skip the keyboard test. The next test, Keyboard Slider, will show you how many times the slider has been cycled, or opened and closed. At this point, you can press the center button and dismiss the Device Info application.
So, how many times have you used your Pre's keyboard slider?
UPDATE: the Hall sensor refers to the number of times the slider was fully extended and closed. The Optical sensor refers to the times the slider was not opened fully.