Friend told me the screen suddenly went "blank" and that the picture "sort of came back a bit a few times some days later but then stayed blank".
I had a quick look today and the 3 other cameras are fine but the 4th one has the following appearance on screen:

Not completely blank as you can see and has a lighter shade either side.
I didn't have time to check inside the camera, connect directly to a hand monitor and have a look at the focus today but will return tomorrow. To my knowledge no-one has played around with the kit.
What do you reckon it is?















