The flash operates via a solenoid wich releases a catch and pops the flash up. There is also a spring which aids the flash to stay up once it's activated. When the flash pops up it releases a micro switch which powers the flash, this is so the flash doesn't work when in the down position.
Emma Jane- yours sounds like the spring has come off.
Alan Potter- yours sounds more like an electrical fault. possibly with the flash charging circuit or the fuse for the flash.
In either case a strip down is required to find out the cause.
daveward712 (at) aol.com
Dave - camera repairs, May 2010