It's pretty basic, being a piezo pick-up under the bridge saddle, into a 2-band pre-amp (Volume, Bass, Treble...), powered by a standard 9v battery. Any decent luthier would be able to check it, and replace any parts that are no longer working properly. The only slightly fiddly part would be changing the piezo strip, but even that is straightforward for a luthier, and shouldn't be expensive. Not to be done by an inexperienced player, but quite within the realms for someone with decent electronic knowledge (our Eldest does this quite regularly...). Take it to a reputable luthier and he/she will fix it in no time at all. There's nothing magic about it, nor 'voodoo' collector that needs religiously preserving, and the guitar itself is well worth getting properly repaired. Hope this helps; good luck with it. It'a a very nice guitar.
Douglas