Hi, I have an E520 with what I think is the same problem. Haven't tried lowering ISO setting yet, but refuse to buy anymore Olympus until it is resolved. Crisp pictures are not too much to ask for. I invested in the 3/4th system, after an awesome OM-4T, and now they've come close to killing the whole line. Cheap is nice, but I'd rather have quality that is inexpensive. I'd also like not to invested in retarded outdated Until further notice, I won't buy any more Olympus unless I can get crisp pictures. And I'm unlikely going to pay a lot to repair what was always there. I may just dump all the lenses and flashes, etc, and go get a Canon or Nikon system. In the mean time, I have a really old crappy Sony quick camera that I use to take pictures. Great job Olympus...
To reassemble, do the same in reverse but keep power supply board more upright than slanted down when re-inserting it in to the lower right corner. The lower right screw post has an protrusion under/behind it and the Power Supply's small 2 wire plug must fit between the front of your Mac and the obstruction. Then it just slides right in and then screw it down.