<p>Hi Chris:<br>
<br />I am glad you got your F4s to work, it is a wonderful camera. One other area, that is somewhat counter-intuitive, for the same type of symptoms is the interchangeable viewfinder. There are contacts there and they a are prone to misalignment. So, my advise is that you don't remove it if you don't have to. And if you do, be gentle.</p>