[Osem]

Yes nothing to lose so I had a look at it and and finally managed to work out how to open it up in the absence of any visible screws on the exterior. It turns out that the entire flat panel on the front is simply glued in place onto a foam gasket so has to be prised off in order to get inside. I didn't remove the whole panel but did enough that I could see sufficiently and found a ribbon connector running into a circuit board which is fixed to the rear of the controls section of the panel. Before doing anything else I decided to push the ribbon connector in a little to see if a loose contact there could be causing the problem. The front panel forms the actual speaker and is vibrating constantly so I'm hoping the ribbon connector had just worked itself a little loose. So far it seems to have worked but it's very early days yet so I'm going to leave it on all day and see what happens. Will report back.