Yeah, ask BCA about checking it. They will probably fix it for cheap. As long as your beacon hasn't drifted too far from the 457 frequency they should be able to do it. Frequency drift is the main reason for beacons becoming not fixable. It will happen eventually, but in general you should get five years out of your beacon before that becomes an issue. After a couple of years though, it's good to have it bench tested anyway. Which BCA will do if you send it in to them.
Once the beacon drifts too far, it's time for a new one.