SP3 stopped recognizing pen tip

[banditmill]

Recently my Surface suddenly stopped recognizing my pen tip. It recognizes the buttons (i.e., opens OneNote when I tap the button on the back) but won't recognize the pen tip. I've poked around before in the HID device list when turning off the touch screen for drawing, so I thought I might have left one of those turned off. But as far as I can tell, they're all turned on. I reinstalled the pen driver but that did nothing. If anybody here has any ideas before I take it in, please let me know. Thank you!

 

[sharpuser]

Battery.
AAAA.

Buy two.

The purple button has nothing to do with the nib (tip). Different devices.
Purple button is Bluetooth, using a coin battery.
Nib is active (always on, creating an electrical field), using a single AAAA.

 

[sharpuser]

Moved to Surface Pro 3.

 

[SeanP]

Same issue for me. Thought it might be batteries so I replaced them. In middle of meeting with customer went out again. I had to toggled between Tablet and Desktop Mode and back again to make it work. Even then it didn't but suddenly started working again.