Manual @ ipdb:
https://www.ipdb.org/files/2253/Williams_1976_Space_Mission_Instruction_Manual_Jan_1976_no_schematics.pdf

Schematic @ ipdb:
https://www.ipdb.org/files/2253/Williams_1976_Space_Mission_Schematic_Diagram_continuous.pdf

My Space Mission had a recently solved scoring issue that has been solved.

Now the previously working top rollovers are not scoring as they should. Both outer ones ((of the three))remain on / lit / will score target value. Noticed the CHANGE RELAY was locked on. Found that the match unit / alternator is not moving - believe it was fine 48 hours ago. Manually advance MU, CHANGE RELAY releases, lane lights both go out. So in my fixing I must have 'mis-poked'. Suggestions please.

Thanks for the come back @Cheddar -

Assume nothing.
I miss the most obvious!

Does the current to the match unit come from a switch on the 10 pt relay or a switch on the 10's score reel or other. I think the unit is not getting power as it worked fine two days ago and hasn't been fiddled with much

So how does that work? Does the 5000 relay close which opens that switch, the motor cycles and just after the 5000 switch closes the 2B on the Long Dwell cam closes causing the MU to advance one?

Tried to clean the 2B and the 5000 pt relay switches - no change - don't think the power is there.

Thanks for input currieddog.

The change relay switch A does cause the rollover lane lighted to be on when the match relay is manually rotated, then of when moved a bit more. As the relay stays locked on if left in that position due to the MU not advancing resulting in a very warm coil, I move it to the position that has the change relay off while troubleshooting.

Did not see the 5000 target EOS note. Will look at that now - then need to pack for pintastic - joy!! Those switches are a pain to view, Assuming the EOS is the top of the stack.

Have yet to get back to it. Pin repair put on hold while a bunch of remodeling projects (including climate control for the basement!) get done! Hopefully can get back to the four stalled projects next month! Kill me to see em stacked and the box from PBR stilling on top.