Re: Ibanez Jen BFP tremolo instability?
Maybe the issue is worn posts, knife edges or both? Or maybe the springs are not matched? If you bought the guitar used, who knows what condition those critical parts are in? In any case, You need a better guitar tech if he can't sort this out. If you are anywhere near CT/RI, I'd be glad to look it over and see if I can spot something wrong. Here is some more stuff I posted for another Jem owner with tuning issues. Maybe something in there can help....
Here are some things that can cause tuning issues with the Edge trems(in no particular order):
1-Adjusting the post height and not first loosening the locking screw(small allen screw that is down in the center hole). Not all Edge posts have this, but if yours does, its important to loosen or you might break the large allen head(these parts are replaceable with Ibanez Rules being a great source). Once height is set, tightening this screw creates a very solid connection from bridge to body.
2-Adjusting the posts with full string tension; this will eventually wear both the knife edge of the trem and the V-shaped part of the post. As those 2 parts wear, they will not always go back to pitch.
3-Brand of strings. Sometimes changing brands will make the difference. For me, Dean Markley seems to hold tune a bit better than D'Addario.(no idea why)
4-stretching the strings(already mentioned)
5- A locking nut that is either not tightly locked, or has loose bolts in the neck. I have seen a few where the locking nut actually moves when the trem is lowered and then returns.
6-Bridge not setup correctly. At rest, the baseplate of the bridge should be level with the top of the body. To set that, I will tighten the springs(or add more), block the bridge so it stops when at the correct level, Tune to pitch and lock the nut, remove the block(the guitar will go way sharp), loosen the spring claw(remove extra springs) evenly on each side until the guitar is back in correct tune. Changing string brands, composition or gauge can all require this to be reset.