Fish Hawk X4 VS X4D Probe

[bassman69767]

Is there an easy way to tell the difference between an X4 and an X4D probe?  I bought an X4D used last year and it wont read the depth.  I think the guy may have sold me an X4 probe and not an X4D probe.  The package he sold me had both a clear mount and a black mount for the display, so I suspect he bought the upgreade kit and sold me the X4 probe.  If I do have the right probe, are there some adjustments I need to make to get it to read depth?