well it has taken me nearly two months to get time to investigate further, and it indeed does look like it is the br1 rectifier. thank you all for pointing me in the right direction. all I need now is to find a replacement part.

Well done, it's common for various bridge rectifiers to die and go short, blowing fuses etc.

I repaired a friends 'funhouse' a few months ago, same thing, blown bridge/blowing fuse.....took about 2 mins to solve it ;-)

MM