[Solved]-D3 zoom breaks mouse wheel zooming after using zoomIdentity-d3.js

The second parameter of zoom.scaleTo(svg, d3Zoom.zoomIdentity) accepts a k scaling factor (e.g., 2 for 2x zoom). The method zoom.scaleTo is intended to be used when you want to set the zoom level, but not the translation (x and y positions).

If you want to set the whole transform to the zoom identity (which resets both the zoom level and the x and y positions), the method is zoom.transform(svg, d3Zoom.zoomIdentity).

If you indeed just want to reset the scale, you can use zoom.scaleTo(svg, d3Zoom.zoomIdentity.k), or simply zoom.scaleTo(svg, 1).