Intonation

[Kmkoenig]

I have a new 712 12-Fret.  Using a tuner, I notice that the second string is sharp on the 1st, 2nd and 3rd frets. Can this be corrected at the nut or saddle?  If, so, what should be done to correct this?  Thanks.

[Ubiquity]

It could be saddle or it could be the bridge.  If the string height is too high at the saddle, the pitch rises when pressed on the frets. When pressing on the 4th fret, you should be able to slide a 0.10mm feeler gauge (≈.004")  just barely between the 1st fret and the string. 

If the bridge bone is plastic,  i would recommend to get it changed to one made of bone and intonated properly.  It's not that big of a job and makes the instrument sing beautifully.

Hope this helps atleast a bit