Nice find--this is one of the rarer Atari titles.

Interesting...I don't think I've seen someone do that before.

Be sure to review the pinwiki page, especially the notes in the documentation section.

http://pinwiki.com/wiki/index.php?title=Atari_Repair

Be sure to read the manual for Space Riders. The manual for Atarians was early and not quite polished. The space riders manual is much easier to understand, and presents the Atari system theory of operation in a more understandable way.

As for the giant MPU board, this diagram should help start to make some sense of it:

Atari MPU Gen1 Board Layout (resized).png

It's not really important at the moment, but something interesting with this particular game--there are no traditional rollover switches. Instead, under the star symbols where you might expect them, you will find a completely different mechanism--inductive sensors.

If this is your first attempt at reading schematics and attempting to do board-level troubleshooting, you sure did pick a challenge. The main problem with this system is not necessarily the difficulty of the system itself, but the lack of "if x then y" repair documentation and community knowledge/support. Normally, I like to suggest that someone cut their teeth on at least two other game systems first (before starting with Atari's system) just to gain some familiarity with the concepts used to operate an early solid state machine. That way, they will be better prepared to tackle this less common game system on their own. That's not to say that this project will be impossible, but since most of it will probably end up being a solo endeavor, you would greatly benefit from working on other common early solid state systems first, especially since there is a lot of repair documentation and community support for those in case you get stuck.

Very nice find
Hope you bring it back to life
And to a pinball show

Curious - where would the other flippers go?

monthly_02_2016_7586de8669375493dd8d9eeef9425bcf-atarians--atari-1976- (resized).png