Though recapping everything is always good, with the SE/30 the most urgent is to change the SMD electrolytic caps on the logic board. That is certainly the source of your problem.
The thru-hole caps on the analog board and PSU tend to last a little longer, so if you're not having problems you can realistically leave it alone for now.
It's only the electrolytic caps that need replacing; the smaller ceramic caps generally don't fail.