So I'm fixing up a williams space station machine that has been sitting in our office for years collecting dust. I've fixed a handful of problems and got it 'working' again, but I'm still facing a few problems before it gets up and running 100%... Also to note, this is the first pin I have ever worked on, I've been lurking the forum and finding tutorials on how to do everything.

1 - every time you turn on the machine it needs to be factory re-set by holding down one of the small black buttons on the inside of the cash door. Once it runs through its cycle, the screen goes blank, and then when you release the button, the game starts up perfectly. I wondered if it was the Batteries that need to be replaced, so I opened up the back glass and found that the battery's had corroded the clips that hold them in place, and had even started corroding the board they are attached to... I assume this is why it has to be factory re-set, but can anyone confirm before I buy a new battery holder? Also what should I use to clean the corrosion off of the board?

2 - The rotating space station ball diverter is almost never lined up properly, and tends to spin either direction randomly when activated. I read this thread:
http://pinside.com/pinball/forum/topic/space-station-turns-wrong-way
Which leads me to believe I may need a new motor, but before I go drop $50 on one, can someone run me through how to make sure its not just the Optos that are bad or need cleaning? Ive never dealt with optos so not sure how to go about cleaning them.

3 - when the ball hits the 'bay door' blocker and causes it to sink into the playfield, sometimes the womans voice saying "Bay doors are open" keeps repeating over and over, and sometimes it seems to be triggered by the ball hitting anything that scores points? I have no idea on this one. any help?

4 - when I trigger 'green mode' none of the lights change. It could be that all the green lights are just burnt out (many of the lights are) but then I would have expected the rest of the field to at least get darker? I watch youtube videos on green mode, and it seems like a very drastic change while I am seeing none. Could it be I just need to find all the green lights and replace them?

Thanks!

Its a fun game. but I'm not sure if I'm a fan of the 'no inlane' design. It makes capturing/controlling the ball almost impossible.