Ok ... I'm kind of a newbie ... but I have done my due diligence and watched YouTube videos on fixing an EM, read Pinrepair's articles, and read up on schematics ... fixed a couple EM's ... but I can't figure out this Space Mission. I got it last night (it is SO CLEAN inside ... I have never seen an EM with copper leafs that are shiny and not tarnished or have "patina" ... this one is AMAZING ... everything shiny ... so don't think that is the problem) ... but it won't start a new game ... it lights up ... but Flippers and Start game button don't work ... the coil to the large chime (on the far right) is continually activated and buzzing ... the coil for the 1,000's score reel (player 1) is continually pulled in ... I tried manually resetting the 1000's score reel to "0" hoping that would let the start up sequence continue but that didn't work and sometimes it advances 1 unit on reel when turning power ON ... if I manually trigger the RESET COIL (in lower cabinet) > then a couple small coils in the Backbox (between player 2 and player 4 score reels) just keep firing .. and the main thing-a-ma-jig in the cabinet with all the plastic gears and leafs switches stacked on top keeps running too... ALSO > checked for broken, touching, bare wires ... and checked contacts on PF that might be constantly touching ... to me that makes sense > it seems like it is constantly trying to score 1,000 points on Player 1 and constantly firing the far right chime (assuming 1,000 point?) ... Guess I didn't learn from the schematic tutorial ... and my "think like a pinball machine" approach is failing me now ... ANY ADVICE WOULD BE APPRECIATED ! I have the original owners manual and schematic ... I just tried to upload a PDF of the schematic but Pinside says the file is too large ... the schematic is available to view on Pinside tho (if you want to check it out) ... HELP ... I may not be able to sleep tonight unless I get this resolved ... just kidding (kind of) ....

P.S. I was going to unsolder the Player 1 coil for 1000's but didn't think that would help ...?

Thanks for replying Howard ... I will try that ! (may have to wait for jimpin1967 to stop over ... as he is smarter than me with electrical circuits) ... will keep you posted ! THANKS AGAIN !

IT PLAYED !! and pretty fast too !! Not sure exactly what I did ... the contact on the Tilt flapper on bottom of PF was almost touching ... and a couple tabs might have been touching on the Set Up Relay ... fiddled with some other stuff too ... HowardR > I didn't get to diagnose that circuit .. but will have to as the credit button still isn't working (have to manually activate the Reset Relay). So just to make sure I understand > hook one end of jumper wire to Blu-Yel wire at the Reset Relay and other end of wire to White-Brown wire on the Credit Unit ... ? ... ALSO, game is stuck on Ball 2 ... sure there are other problems ... but at least it played and scored ... Can deal with the little issues tomorrow ... I can get some sleep now ... THANKS Howard !

HowardR YOU ARE A GENIUS ! I ran the jumper wire and the credit button worked ! (only for 1 player tho .. if I hit the button 2 or 3 times it didn't advance to Player 2) ..... SO WHAT EXACTLY DOES THAT TELL US?? BTW > before I ran the jumper wire > I checked out the Ball Count Unit (since that is on the schematic in between the Reset Relay and Credit unit) ... It wasn't moving freely so I cleaned the coil sleeve and plunger and shortened the old spring ... that seems to be working fine now ... Balls advanced correctly and at end of Ball 5 the game ended. SO I'm guessing there is a problem with the Player Unit or Game Over Relay (I don't see a relay labeled Game Over Relay ... ?) .... I will go investigate further ... message when you can .... ALSO > the previous owner said this was set to FREE PLAY (don't know if that makes a difference) ...
P.S. you helped me a couple months ago on my Jet Spin ! That one is playing AWESOME !! THANKS !

I fiddled with a few more things and played the game ... and now the Credit Button working ... but still only for 1 player ... maybe the machine is working it's own bugs out ... I go play some more !!

Nothing at all ... Maybe problem with Player Unit ?? or Credit Unit zero break switch?? I will fiddle some more ... not too worried at this point ... some problems seem to fixing themselves ... At least it plays !

Also, I was able to identify and locate the Game Over relay > had a drawing of it in the Owner's Manual (and showed what 2 coils were on it) ... YAY ... The Owner's Manual is more detailed than my other machines !!

OK ... I marked that with Blue tape a couple days ago (as a potential problem) as the leaf switch is bent a little funny ... but didn't know if it was really a problem as game is supposedly set to free play and that wasn't on the initial list of stuff in the circuit... guess it is ...
OH $#IT ... I though the Coin Unit switch was on the circuit above in the schematic .... now I see there are 4 paths .... (pause ... for swearing ... lots of it) ... I'm feeling stupid ... SORRY ... don't mean to waste your time ... what a learning experience tho ...

And your not going to believe this > but I have a Space Odyssey that I am working on also ... credit button was working .... until tonight > when I was trying to adjust the rewind (?) spring on the Player Unit (while game was on) ... and spring hit a solder tab and on the advance coil and sparked ... replaced a fuse > but now that credit button isn't working either ... OMG .... this would be comical if I wasn't living it .... LOL ... well, my fault ... tired now ... gotta vegetate in front of TV and get some sleep ... jimpin1967 is coming over tomorrow .. maybe we can try to figure this out ... THANKS for hanging in there with me !!!
ByTheWay > I drove 3 1/2 hours on Friday to get the Space Odyssey ... then Sunday night the Space MISSION comes up for sale on Craigslist for $100 less and it's only 1/2 hour from me ... and THIS IS WHY I have 2 not-exactly-functional pins in my basement right now .....

Who needs sleep ... I THINK YOU CALLED IT!!! (see photos) ... I should take pictures all the time ... I couldn't see this switch wasn't making contact when I looked at it from above (it's in cabinet) ... I will go adjust it and report back ... (I did see it was bent wrong, though maybe they somebody did that on purpose to make it Free Play) .....
BTW> one thing I really don't understand is how people make pins Free Play .. and all my pins have wires going to coin door that have been cut ... so I don't understand what relays (or other things) that takes out of the equation. I watched a video on Youtube and guy put alligator clips on contacts on credit unit (??) and BAM if was Free Play ... why all my pins have wire cut on coin door??? Well, that's probably a whole different post .. just ranting ...
If anyone else is reading this > they are probably getting a chuckle out of my inexperience ... ahhahahha ...

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DANG ... adjusted blades ... Credit Button still not working ... if I manually trigger the Reset Relay then I can play a game ... this time I triggered Reset Relay 4 times and I had 4 player game ... don't think that was working before ... ? but not sure ... OK > I have to get some sleep ...
ONE LAST QUESTION for tonight > Why aren't the contacts lined up on that leaf switch?? (the dot/rivet things) ...? ... Space Odyssey doesn't have the same stepper unit to compare it to > but isn't that WRONG ? .... ? ... shouldn't the rivets line up ? Could someone have replaced the blade with the wrong one and that is the problem ?? or would it still make "enough" contact touching the copper ??

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P.S. just noticed in photo ... the bake-a-lite insulator strips (?) are different colors ... leading me to believe that maybe someone change the switch blade at some point ... YES..??

HowardR > You are a man of few words so I should order new switch ?

Sorry for delay in replying ... Yesterday, box of stuff from Pinball Resources came in mail ... so was busy doing some "easy" stuff ...
In Space Mission cabinet > there were some pieces to make leaf switches > so tonight made and installed a switch with contact in correct place ... works periodically. the Coin Unit stepper doesn't seem to be moving freely so will research tomorrow what to lube it with ... have some Super Lube from Harbor Freight (not sure if that is good for that?) ... below is a photo of new contact ...

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Update > THE CREDIT UNIT APPEARS TO BE WORKING ALL THE TIME NOW !! .... I was going to set the game to Free Play by putting an alligator clip on contact in credit unit (someone recommended doing this to by pass some of the circuits and make diagnosing problems easier> in another thread) ... When I was doing this I noticed one possibly crappy connection from wire to advance coil ... also noticed I couldn't get the credit wheel to show Zero in the BG because the post on the gear would hit the switch when credit wheel got down to 14 credit ... so changed that so could get to zero ... but now it will only go to ~7 credits and then the other post hits the max. credit ? switch ... so now I have to figure that out ... LOL ... For now I am setting it to Free Play ... when hit credit button it starts as a 2 player game ... so I will have to figure that out also ... ANYWAY ... it appears the Credit Button problem is solved !! THANKS HowardR .... I will start a new thread if I can't fix other issues ....