Following a false alarm (siren only) on my G3+ system, now neither the siren or the strobe work. I have checked out the system using the alarm and walk tests in the installation manual and all tests are OK except those for the strobe and siren. The siren/strobe fuse (F5) is OK and the strobe power is 12v, however, the siren +12v at terminals B and D is not present. The internal sounders are OK and all other alarm functions appear to work correctly. I have not examined the siren/strobe box (Sonade) as yet (height issues!). I would appreciate any ideas