Cheers for the heads up, i pulled the board out yesterday to find that someone has done this before me but only replaced 4 out of the 5 15kufd caps.
the attached photo is before i did any work and as you can see they had exactly the problem you were talking about.
Turns out i was an idiot and ordered the wrong bridge rectifiers, i did not realise they are a wire leg and not a spade leg ><
