GI flaking out / flail & shield optos quitting.

Howdy, I have a BKSOR on route and yesterday I got a call saying the GI was going out sporadically and the shield would not lift to allow ball in, as well as the flail not working. I browsed the forums, and it appears others have had similar issues. However, I never got a concrete answer on what the solution is/was...has there been any word from Stern on what exactly is causing this? I suppose those of you who have gone through it will know right away, but I don't see it being a widespread issue.

Anyone got any advice? I'm heading up to grab it tomorrow, and hope to have more info on what I'm about to deal with...

Thanks in advance.