tuning problems in JS32 7q indonesian made 7 string guitar

[landabu]

Hello. I have purchased this JS32 7q Jackson but it has several low B tuning problems, can somebody tell me if it is common in this model or a way to solve such a problem?

[toejam]

Welcome to the forum. Has the string been stretched enough? Maybe it's an old or dead string and needs to be replaced?

[Mudlark]

Maybe the nut slot is binding the string?
Try some pencil lead shavings in the slots. Use a razor blade or utility knife to scrape the lead.

Switch the B tuner with another to see if the tuner is at fault.

[Force]

The intonation on that string might also be out so the saddle will need adjusting. Compare the 12th fret harmonic to the 12th fretted note, if the fretted note is higher in pitch, the saddle needs to be moved backwards.