Here's the view underneath. The printed circuit board has to come out, of course - it's double sided and most of the components are on the side you can't see. Deep, deep joy. There's clear evidence of a burn-up at the top centre of the board (just below the bunch of green wires) and a quick peek with an inspection mirror confirms that the burning is present on the other side too. There's also some evidence of previous repairs in the same area, suggesting that we may have an ongoing problem here.