What could be wrong with my guitar?

[Ironside]

So, tonight I was practicing with my Rg752lwfx tuned B-standard.

When I play the open 7th string my tuner was showing "B" bang on, and when I checked the 12th fret, same thing; "B" right on the money.

The problem was, whenever I played the 3rd fret on 7 (D) it kept coming up sharp.

What the heck is going on here??? What are some things to check for? Is something out of whack?

I know it seems totally random but the song I'm learning (Weeping China Doll) uses that D on 7 and it kept sounding way off (which led me to check it with the tuner)

No matter how many times I tried tuning it, it was off.

The other day I noticed the 4 screws on the back of the neck were slightly loose (not loose I guess, but not snug like I figured they should be) so I tightened them up SLIGHTLY - could that have messed something up?

 

[cult]

Tightening the screws can't mess stuff up unless you overtighten them.

What could be wrong?
Low 2nd fret. You'd have to press down the string too much then. Wouldn't account for a really dramatic change in pitch.

High nut is what I'm thinking. check the 1st and 2nd fret. if they go sharp as well, you should file the nut down for the strings.

If the nut isn't too high, then a fret would be misplaced. Not easily fixable.

 

[Solodini]

Sounds like your action there is too high, so you're bending the string sharp by fretting it, or you're fretting too hard which is bending sharp. Mess about with vibrato by picking a note andvarying how hard you push it down to the fret and you should see what I mean.

 

[bostjan]

How sharp? A few cents? Many cents? A half step?

Sounds like your action there is too high, so you're bending the string sharp by fretting it, or you're fretting too hard which is bending sharp. Mess about with vibrato by picking a note andvarying how hard you push it down to the fret and you should see what I mean.

But if the neck is straight and the action is too high, whatever problem occurs at the third fret must be as bad or worse at the twelfth.

 

[Solodini]

Could be as Cult mentioned, high action due to the nut being too high. If the nut is high and the bridge is low, the action could decrease as you go toward the higher frets.

 

[Bearitone]

Even when a guitar is perfectly intonated, not every note on every fret is dead on perfect.

Thats why the "true temperament fretboard" was invented.

This MAY be the problem you're seeing. I may be wrong. Either way check out true temperament.

 

[gogolXmogol]

3rd unwound string always is a bit tricky to intonate, as for the low B, 99% that its just way to thin (about 56 or so), the very minimum for decent intonation on 25.5 is at least 60 gauge, judging by my personal experience of course!

 

[erdiablo666]

The intonation may be off, or it may be any of the things that the folks above mentioned. What part of Ontario are you in? Can you take it to a tech to have it looked at? I disagree that you need 0.060 for a low B. Lots of folks here, including myself use a 0.056 with great results. It's all personal preference.

 

[gogolXmogol]

Well, it all depends on preference of course, but there sure is a tension minimum you want to have on your low strings.
http://www.youtube.com/watch?v=uzNAmY6RYsM

 

[bostjan]

Even when a guitar is perfectly intonated, not every note on every fret is dead on perfect.

Thats why the "true temperament fretboard" was invented.

This MAY be the problem you're seeing. I may be wrong. Either way check out true temperament.

I don't think that's what we're talking about here.

True temperament is actually a tempered tuning, not a way to correct mechanical deviations.

The notes on a properly made standard fretboard should intonate perfectly (i.e., within a specified tolerance) with the notes on an equal tempered tuning system.

A true temperament fretboard moves certain notes away from equal tempered tuning to make them sound sweeter, but according to a standard tuner, they will be off by up to four cents.

Well tempered tunings have been around on piano since before equal tempered tunings existed for those instruments. Fretted instruments just used equal temperament as a convenience.

So, it's not that a perfect fifth is NOT 700 cents, the fact is that a perfect fifth is defined by a tuning system, either in 12-EDO as 700 cents, in JI as 702 cents, in 19-EDO as 695 cents, etc., because the tuning system is necessarily man made.

/OT