Strange Tuning Issue

[Daniel Sorbera]

I have an old 1976 ibanez LP custom clone that I put some new tuners on, after the change I strung it up with some 10 gauge boomers. But it had some very weird intonation issues that I cant explain.

It played perfectly in tune everywhere except the 3rd, 4th, and 14th frets on the A and D strings where it would be extremely flat. Like if you fretted the A string at the 2rd fret it was perfect, but move up to the 3rd/4th frets and it was dead flat, back to the 5th and it was perfect again.

After changing the strings to a new set of the exact same kind of strings it seems to have fixed the problem. Is there any other reason that this problem would occur and is there anything else I should double check on the guitar?

[7even X²]

Nope, you hit the nail on the head. You had one dead set of strings. I have bought boomers before and had the same issue you seen.

As for anything to double check on the guitar? If you changed the strings gauge at all, you'll need to look at the nut grooves as well as the tension on the neck. If you had heavier strings on it to start with, then the nut has larger grooves and the neck is set to compensate for the string tension difference.

Hope that helps some

[j. pierce]

A kink in a string can make these weird things happen. Squish a package of strings hard enough to do this, or bend the string enough in the process of stringing up. I've had this happen to a package of strings in that were kicking around in my gig back and got sat on. Often times if it's wound strings, you might not even realize that they've been kinked until you look at the windings of the string and notice something looks off.