Looking for a little help/guidance.

I'm completely new to the pinball repair world. I recently acquired a Williams Space Odyssey machine.
It was in my wife's family's basement when she was a kid and has not been used (or even powered on) in at least 10 years.
Luckily, both the playfield and backglass (?) artwork is in surprisingly good condition. I don't think I'll need to be be doing any type of cosmetic improvements.

After posting on this site earlier (different forum), some helpful people pointed me towards a basic repair guide which was exactly what I needed for a starting off point. I've read/watched a lot of info since and then felt comfortable powering it on and checking it out. BTW, I have a strong background in electronics and electro-mechanics - just unfamiliar with pinball machines specifically. I've done some basic stuff on my own on the machine and with enough time could probably figure things out myself but I'd rather rely on other people's experience instead of having to learn by making mistakes (and likely damaging stuff).

Here is what the initial status is...
All of the fuses check OK.
The machine powers on and most of the lights come on (I'm assuming some are burnt and I plan on replacing all).
The score counters reset to zero (when the start button is pressed)
The only items which seem to function (on the playfield) are the 4 areas that capture/detect/eject the pinball - 2 at either side of the drain area and the other 2 (different style) about midway up the playfield.
None of the scoring areas/targets function. The flippers and pop bumpers don't function either.

So, being adventurous (and not wanting to bother people with REALLY basic stuff), I went through the whole machine and manually activated all of the solenoids and did a basic visual of all of the switches. I found one stepper unit which definitely needed cleaning and another (Bonus Unit) that was iffy. I also found one relay/switch unit (.10 coin unit) which was partially disassembled/misaligned. I cleaned the first stepper unit (basic step-up only) with no issues. I cleaned the second one, which is a step-up/step down unit. The mechanics all function smoothly now but I am having 2 issues with it.
-The first one is arguably my fault. I didn't notice that the gear (toothed wheel?) has a small area with no teeth and so I didn't note the alignment between it and the finger switches (?) which it turns on the other side of the Bakelite board. Any idea where I can get (or figure out) the alignment?
-The second issue should be a basic alignment issue but I'm having trouble with it. I had to remove one of the switch assemblies in order to remove some of the mechanical components for cleaning. I did take photos prior to doing anything so I can see what it should look like. The issue I'm having is that after re-installing the switch assembly, it is not being activated by the post on the metal gear (as it was originally). There's not much play in the installation position so I really don't understand why it's not well aligned now. A side-note is that after removing the switch assembly, I found a Bakelie spacer on the floor, which I didn't notice coming off but it seems obvious/logical that it belongs with that switch assembly. It's the only one that I took out. I've made a best guess about which side of the switch assembly it belongs to but I may be wrong (it's happened once before ). I've attached a photo. Perhaps, if someone has the same stepper unit, they can count the spacers for me or just send me a close-up photo.
-Finally, I'm having trouble restoring the relay/switch assembly (.10 coin unit) at the bottom of the playfield cabinet. When I push the metal activating plate manually, the N/O switches are not closing. I've read at numerous places where switches can be adjusted but I haven't actually seen the method for doing so. Is it simply a matter of bending the metal fingers? I hate bending things instead of adjusting so I just want to make sure that's the way it's done before I mess something up. I can't see any obvious way to adjust the switches. I suspect that this relay/switch assembly was worked on by someone else previously, due the the partially disassembled state in which I found it. Additionally, I noticed an "open air" connection nearby which looks like the original wiring for one of the connection terminals (2 wires) but with a short wire attached (see photo). Not sure why this would have been done. It looks like the 2 wires are long enough to reach the terminal without the short wire extending. The connection does not seem safe/secure/smart like this. am I mistaken? There is also an unconnected wire at the nearby wiring harness but I'm not even sure if this is an issue or not. It's not long enough to have been connected to anything nearby.

Hopefully, the photos are clear enough(if my descriptions aren't). If not, LMK and I'll try to take some better ones (or give you better descriptions).

Thx in advance for any help you could provide.

So, for now, I need a little help with these 3 items.
Once I get past this, I plan on doing a quick basic cleaning of all of the switches

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Thanks for all of the good advice and reference materials.
I've managed to correct all 3 of the issues noted in my previous post.
Additionally, I cleaned/rebuilt the another stepper unit in the backbox, which definitely needed some attention.
I was hoping that fixing up these 3 stepper units plus the .10 coin relay would've advanced me somewhat but I'm still having the exact same symptoms as I did the very first time I plugged it in and tried it.

Specifically (at the risk of being redundant)...
All of the fuses check OK.
The machine powers on and most of the lights come on (I'm assuming some are burnt and I plan on replacing all).
The score counters reset to zero (when the start button is pressed)
The only items which seem to function (on the playfield) are the 4 areas that capture/detect/eject the pinball - 2 at either side of the drain area and the other 2 (different style) about midway up the playfield.
None of the scoring areas/targets function. The flippers and pop bumpers don't function either.
The ball does not get moved from the drain to the start position.

From everything I've read and seen so far about repairing EM machines, it seems to me that the stepper units and switches are the most common trouble areas. I've addressed all of the stepper units and was going to do a light, non-invasive cleaning of all of the switches (while closely inspecting them for other issues) but have been warned off of doing so.
I am going to try to figure out where the unconnected wire belongs. Looking at it closer, I can see that it does have solder on it which suggests that it does belong somewhere and has broken off.

If anyone has a similar machine, perhaps sending me a photo of that relay and the associated wiring would be faster than me trying to track it down in the schematics.

thx again

You seem to know your stuff!
Although not working yet, this does give me a good jumping off point to start troubleshooting the problem.

With power on, when I manually activate the game over relay, it latches in that position, the "Game Over" light goes out and ball "5" gets displayed instead.
Additionally, the score for Player 1 advances by 100 points every time I do this and one of the chimes sounds.
The big issue is that there is a loud hum that is audible while the relay remains latched. I can't identify where exactly that's coming from yet because I am releasing the latched relay (manually) quickly out of fear that I'm about to burn up a coil.

Someone mentioned that I can get schematics, etc. from IPDB - What is that exactly? I'm not familiar with this acronym. Can someone please elaborate?

OK, so I may have spoken too soon.
I thought that all of my stepper units were working well but after watching a video that clearly shows that the Ball Count stepper unit, located in the backbox, is a step-up/reset type, I can see that mine was NOT working as it should. It steps up nicely but will not reset well, if at all.
When I remove the "spider contact unit" it works flawlessly. Upon closer inspection, I'm suspecting that someone (not me - I swear!) has bent the fingers excessively, likely in an ill-advised attempt to get it to work better. I'm fairly sure that this is the issue but, being a newbie, I have no reference to compare this against. Some of the contact areas appear to be facing almost sideways instead of down (when it is removed from the stepper unit and relaxed and there is a wide difference over how much deflection (from resting position to contact) there is among the individual fingers. I believe this is causing excessive resistance to the motion of the metal gear which drives it. I believe I'm going to have to bend these back to their original positions but I just wanted to check with the experts to confirm this.

Can you please look at the photos and let me know if you concur?

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