i have figured out what the intermittant problem on my minolta camera was, a loose ribbon connector from the ccd to the main pcb. if i twiddle it with a tweezer i can get the picture from the lens back.
is there any trick to improving connection of a ribbon connector? it has around 20 tracks. the only thing i could think of is to make the ribbon thicker with clear tape on one side.
if above is unclear this is a similar connector: