help – Mistral freezer dead

Model no is FZ60P

My Hotpoint Mistral F/F Freezer was icing up, so I took out the internal back panel and saw about 6″ of ice from the Drain chute (excuse lack of tech terms!)up to the Evaporator thingie.

To melt the ice quickly, I used a hot Air gun, which you may tell me was a bad idea, but I was careful to not to overheat anything apart from the ice…

…but now the freezer is apparently dead, no lights on, although I have measured 240V on the connection panel inside at the top left.

Any ideas what might be wrong? I would have thought the lights would always come on, unless there is some master fuse that has blown.