On my Jazz Bass neck, the fourth fret seems to be a little higher than the others, so I checked it out and there's a little gap between the bottom of the fret and the top of the fingerboard. Is there any way I can compress this and fix the problem without taking the bass to a shop? It is really important to me since it makes all the frets below the fourth buzz like crazy, and playing the music I like just sounds terrible. I appreciate any help you guys can give me. Thanks!
Don't compress or hammer it in. That could make that fret lower than the rest. I would just dress it down (file it), until it's level with the rest. Though, the fret might not be seated correctly, in which case it's probably better to have a good tech look at it. It's possible the fret will continue to move. I had a MIM P with a high fret. I just dressed it down. It never gave me an issue again.
For a properly-equppied technician this should be a simple and inexpensive job. But it depends a bit on why the fret is high in the first place. Whatever you do, don't just file it down. If the fret is not seated properly you will just create a further problem by filing it. The approach I would take would be to re-seat the fret first by using a proper fret press. If it stayed seated I would return the bass to you and have you use it for a while to see if it raised again. If it did I would look at other means to seat it more premanently. However, it may spring up immediately after re-seating. This calls for a bit more work in seating it, and consequently a bit more $$ to have it done. Also it is possible that the fret slot was not cut deeply enough or that there is some debris in the fret slot. In such a case the job is a bit more pricey since the fret will have to be removed and the fret slot cleaned and/or deepened. If the fret doesn't have to be removed, the job shouldn't cost any more because the board is bound. But if the fret slot has to be deepened - that's the costliest scenario. Sound complicated? - it can be. My best advice is to take it to a competent luthier/tech.
Get a quote if you're worried about the cost. For a single fret it may not be bad. That being sait you may need to have the frets dressed for a tech to tackle it which would cost more.
Turnaround's advice is spot on. It is the intelligent, conservative strategy. It is also minimally invasive. It protects the client's pocketbook. If the fret is "popped" this tactic will cause more problems than it will solve. A popped fret is the condition where the barbs on the fret tang are no longer engaging the walls of the fret slot. That portion of the fret is allowed to float. Fret wire is springy stuff. When a popped fret is dressed, it will react like a diving board. The file will take some off the top of the other frets while pressing the offending fret into the widened slot. The result is that the popped fret will be higher than the surrounding frets. The remedies for a popped fret are gluing the fret down or replacing the fret. A skilled luthier can often glue the offending fret level so that it requires little or no dressing. Fret replacement will require spot dressing the entire area. As Turnaround pointed out, if the slot is cut shallow or there is debris in the slot, it will cause the fret to sit higher than the surrounding frets. The fret is stable and can be dressed level.
Dan Erlewine has a very good discription of how to glue down a loose fret in his Guitar Repair book. I've done it, and it works well. Ed
Thanks for the advice guys. I found a Fender Authorized repair guy in my town who says he can take care of it. Hopefully the warranty will still cover it. Fingers crossed!