Usually, the stylus needs either new batteries or a re-pairing through Bluetooth The Microsoft Surface Pen adds extra functionality to your Surface, but this stylus isn't without faults.

The Surface Slim Pen is Microsoft’s latest and greatest in stylus technology – integrated ... When you’re ready, use Bluetooth to pair your Slim Pen to a Surface. If you have a Surface ...

But don't worry, whatever Pencil model your iPad supports, this guide will explain how pairing works. As the oldest stylus in Apple's stable, the 1st generation Apple Pencil is compatible with ...