Hi All,
This request may not be for the faint of heart!!!

I picked up a non working SO about 6 months ago, it would not complete a new game start sequence.

It was very dirty. I cleaned all the score reels and steppers in the back box which helped get me closer and the game now does usually complete the new game start. I got discouraged though because of the issue below and have ignored this machine ..until now....id really like to get it working for Christmas flurry of pin action! It is going to take a pile of work though and I really hope to get some coaching.

I have this persistent problem between the score reels and the chime coils locking on. For example, when activating the 10 point bumper above the flipper and increment up to 90 all is ok, then when the score should roll over to 100 the 100 score reel does not fire but the small chime 100 point locks on with a loud buzz. I shut the machine off when this happens. I wonder if I have reassembled the score reels incorrectly to cause this?

This is a very dumb question but how does one start a 2 player game? Simply hit the start button twice at the beginning (after credits added) of new game? The machine does add credits and subtracts accurately.

As I was fiddling around trying to get reacquainted w the problems I walked away from months ago, I noticed It seemed I was on 2nd player because the little red 2 light on the bottom right of the back glass was lit but the big 2 beside the 2player score window was not lit and did not register any score. Problem. Then I notice the spinner 1000 when lit was on so I flip the spinner once and the 1000 chime coil locks on ...exact issue as the 100 chime,...problem. Why the spinner was lit for 1000 is another issue...guessing bonus stepper unit?

Why are the 100and 1000 chime coils locking on? But not the 10 pt?
I'm a newb and chasing several issues which makes isolating the problem areas tough for me. I could really use some coaching to help break this project down into manageable pieces. I have watched Steve Furys video several times on YT and wrote down all the steps. Yes I have the schematic and orig manual. Spread in front of me here at the kitchen table.

Even as I reread this I'm shaking my head. Any advice on the score reel and chime coil lock on would be very welcome.

First off, thank you all for taking the time to read through my first post and then provide such helpful information!!
Between you you have given me a bunch of tips to investigate. I will re visit the score reels and player unit and ball count unit and report back ...likely with a bunch of new questions!

Thank you Steve that is very helpful.
So some good news is that I cycled the 10 and 100 score reels with that animation in mind and it looks like the end of stroke switches on both are not opening ...regardless of number on the reel. I also noticed that they were very grotty and also the open @ zero, 9th pos etc switches are also very grotty...EM dust/grime. I was so focused on the reels and really did not understand the importance of the eos switches.

So I will pull off the back box now and get out the saw horses to go through each carefully. Some serious business card action needed! Those eos switch blades look very light and would not need much to give a mis adjustment the other way...always open ..will be cautious. Like Steve said I'd like to keep the machine orig and function as it should without "mods".

Tempted to just give a quick tweak and see if I'm on the right track.

Discouraging. Gave the 10 point reel eos switch blade a small adjustment, studied the 9 and zero set of 3 switches on this same reel and they all seem to be working as per the animation. So I fired up the game and tried 10 point scoring , get up to 90, then 100 reel does not fire to read 1 but the 100 point small chime dings and coil locks on. Buzzzzzzzz. I guess I can only score 90 points max! I feel really dumb right now...

Also, player 1 lit up and scored on this display yet the red player 2 light on bottom right? Also cannot start a 2 player game. I got issues! So take the backbox off or keep troubleshooting in situ? I like everything plugged together and now I cannot lay so much blame on the dirty switch stacks in my post above ...they seem to be functioning as intended...at least moving closed and open, but the 100 point relay and chime lock on as described and this sucks arse.

Just tried ball count unit to see if I could end on a positive tonight. Started game, scored 10 points, score the 1000 point side drain big chime dings once, does not score 1000 but the chime coil locks on. And the ball count does not move to ball 2! Does go from game over to ball 1 though...

When the machine completes a new game reset, should any of the middle playfield bonus lights be on? Ie 1000 is lit?
Does not make sense to me that it should but I have never played the game before , I guess I'll watch a yt video now.

At this point I wonder should I start to disassemble the machine and start a general clean of every switch and relay? There is not sparks flying around like some seriously bad connections, but I can't understand how I have so many bad things going on at once.

When the 1000 point relay was locked on (and chime) on one test, I accidentally hit the 100 point relay instead and it immediately locked on, I think the chime went once (which it should, but the coil locked on as well). What a gong show!! need to go to a happy place now!

Here is the deal. .. The 10, 100 and 1000 score relays move freely without any current involved. As soon as the machine is powered up and a game started, if you increment the 10 point score relay manually in the back box...no problem ,,, ding...ding....scores by 10 every time. Awesome right!?!

THEN when you try to same thing with the 100 score relay,....as soon as you even lightly touch the relay, it pulls in, sticks on, dings once on chime, chime coil sticks on and the relay is stuck on...all while it does not even score the friggen 100 points!!!! Argggggg! Does the exact same thing for the 1000 point score relay also!!! But not the 10! All good with that one.

Sorry for the long post and rant.

Thanks so much Rolf for your advice and trying to help. Greetings!
Honestly starting to think this machine is possessed. And, it sat for years as basically no one could figure it out but it looked nice in the corner of a shop all lit up ...which has resulted in severely cupped inserts, and the playfield paint is medium shape at best. Aye...aye aye.. Off to a rocky start for sure

Hmm, sorry Rolf but 1/2 my reply in the above post is imbedded in the block quote from you.
Looking forward to any suggestions, I'm lost.

Hi mikala, I thought of that too, stuck on playfield switches but wouldn't they then lock on as soon as a game was started?

Well, it looks as though I'm going backwards and the machine has decided to put up an extra fight. The machine will now not complete a new game start up sequence. It will add and decrease credit, switch from game over to ball 1 in lower left display along w player 1 score window lit, but will not reset the score reels and the score motor just spins.

Before this started though, I did learn one thing trying some of your advice above (thank you). On a fresh new game reset, I incremented the 10 score relay up to 90, then at 100 the 100 score relay activated, 100 pt chime goes ding once, chime coil and score relay are locked on....AND the 100 point score reel plunger did not move at all!! When I manually activated the 100 score reel plunger to score a 1, the eos switch worked, and broke the current to the buzzing locked on coils...they released.