[Shiraz (Ray)]

Aaaugh - an intermittent. At least that rules out stray light - it's a power problem.
I would have a good look at the cables and maybe replace the main power lead - those wires look fairly fragile. My problem was poor soldering inside the camera, but I wouldn't open that up unless there was no other option. Probably worth checking with Theo again, now that the symptoms have changed - he knows everything there is to know about these cameras. All the best, Ray