So my fifth string has been buzzing when played open. I think it started doing this after I had the frets replaced and the guy adjusted some things for me. I THINK the reason for the buzzing is that the neck isn't even with the tension hoop. I think just slightly leans to one side, making the fifth string closer to the fret board than the others strings. So today I took the strings off and loosened the coordinator rods so that I could try to align the neck correctly. I could push the neck to the correct position, but as soon as I let go it moved right back to were it was before. So I'm not really sure how to fix this problem.
I have attached a picture of the neck and tension hoop to show how it is not aligned evenly
I expect Beegee has the issue, being at the pip. Take your fingernail and push down on the string just in front of the pip to see if it stops the buzz. It also appears the end of the fingerboard is against the hoop on the sides, accounting for the neck always going back to the same place. Is the neck tight against the tone ring or is it being held off by the fingerboard/hoop meeting first?
From that pic. Your finger broad is up against your tension hoop? There should be a gap between the finger broad and hoop. Looks like it is pressing in to the hoop on the 5th string side. Change your 5th string. Maybe it is a bad string
While I don't think your neck alignment is causing a 5th string buzz, I too had a conversion neck that seemed to naturally want to rock slightly off kilter, like it was rotated a degree or two to one side. There was enough "slop" in the lag bolt holes through the rim that I could manhandle the neck into proper alignment, and like in your case, it would rotate a degree or two "off" while I busied myself tightening up the co-ord rods.
As Mr. Davis suggested, I had to grip the neck with my left hand with the "claw of death" whilst I tightened up coord rod nuts with my right hand.
All this made no difference to sound, but I'm just OCD or feng shui sensitive enough to be be driven crazy by the tilted fingerboard.
Basically a tiny problem with lag bolt location/trueness in the new neck.
Unless the underside of your 5th string is rubbing on the top of the tension hoop, alignment is not the source of your buzz.