At a rehearsal a two days ago, I took out my mandolin, to find that the action had suddenly dropped, to sch an extent that there was a buzz on every note and some notes above the 7th fret did not sound at all. It did not take long to work out that a soundboard brace had come loose. I have traced this to what seemed at the time to be quite a small knock about a fortnight earlier (I had not played this mandolin during that time). The mandoling in questtion is nothing valuable - a laminate-topped, oval-holed 'A'-style, bearing the name 'Harmony', probably built in the early 70s - but it excelled in its playability and, with the addition of a piezo transducer, has served me very well as a gigging instrument over the years. So I think it is worth the trouble of repairing it.
I have repaired loose braces before on larger instruments (guitars and basses). The problem in this particular case is accessibilty - the soundhole is small and partly obscured by the fingerboard extension, so there is no chance of getting in with my hand. The brace that is loose (the only brace in the whole instrument, in fact) is of the transverse kind, under the bridge. Since there is a 10th fret neck-body join, this is a long way from the soundhole.
I have been trying to think of possible solutions, and the easiest would seem to be taking the back off. But I would like to avoid this if possible. Can anyone offer any tips on how to do this job through the soundhole?