If you upload them somewhere else like youtube or vimeo, you can paste the link to it here.

Yes, the voltages after the transformer are the same.
It is only the input voltage to the transformer that changes.

Before going further check all the fuses to make sure they are the correct value. Great info here:

https://www.pinwiki.com/wiki/index.php?title=Bally/Stern

There is a 1 amp slo-blow fuse under the PF that controls all the solenoids except the flippers. If good, check for 43VDC at the coil, orange or yellow wire. The coils are daisy chained with 43 VDC.

Pinwiki should also tell you how to verify the solenoids would fire if they are wired correctly. You basically ground the tab to verify the solenoid fires. I recommend running the self test first and see if any/all solenoids fire. You should be able to find the manual and schematics on IPDB.org

The "Aid" 40 pin connector at the top of the MPU is for a test fixture Bally sold BITD, it can be ignored.

https://www.ipdb.org/files/2252/Bally_1980_Space_Invaders_Manual_with_schematics.pdf
PDF version of schematics so you can zoom in and make it easier to read.
http://www.techniek.flipperwinkel.nl/ballyss/rep/index1.htm
Also check out this repair guide section 1g, it has all test points for all boards and what they're supposed to read approximately

If the buttons on the door like start and test don't work, try reseating the plugs on the MPU.

Is there acid damage on the MPU from battery leakage? If there's a old barrel-style Ni-Cad battery definitely install a remote battery in a holder, a memory capacitor or NVRam (best option but more expensive). I would also consider doing some preventative maintenance if the game hasn't been worked on in a while. Go through each board and reflow solder joints on the header pins, do at least a couple of the ground mods on the driver board, repin the rectifier board (male and female), change the 20a fuse clips on the rectifier board. These things likely will not fix your main problem but they will help prevent problems down the road. If you have the means maybe take the game from the location to your house.

Ciccoball - Following or participating in this forum, from my perspective, is always informative and welcomed. I read all of the new topics, and if one interests me, I'll read the thread and possibly comment. I only comment if I feel it would be helpful. As with any forum there are always going to be a few that abuse and ridicule, but those are far fewer on this website than on others.

Don't worry about just reading posts - I don't think anyone is going to call you a stalker. The more posts you read, the more you will learn, especially in the tech sections.

Like suggested, try to get the machine near you so can keep the troubleshooting going when you're in the mood to work on it. SI is an enjoyable game for me, so I really like seeing them restored into usable condition.

One other thing - this website is full of helpful people who all contribute to the tribal knowledge of pinball and pinball repair. There are no monetary rewards for following/reading posts. (At least none that I have found )

The link to the video tells me its private and I'm not allowed to view it.

Cut that 1990 battery off that board ASAP. It has leaked and the acid is eating the board. There are ways to remediate that damage. It also looks like it has leaked onto the cable clamp below (and maybe more).

https://www.pinwiki.com/wiki/index.php?title=Bally/Stern

Your CPU is booting up in the video. As mentioned earlier, verify the 1 amp SB under the playfield is good.

After that, run the solenoid test to verify all the solenoids work.

OK - the closeup was too close, but I am guessing the corrosion has migrated across the board and into some of the components on the MPU board. If so, at a minimum, check the connector J4 that goes to the MPU. Chances are really good those pins inside the connector are corroded as well.

Make sure you get all of the corrosion off of the board, including under components. If you don't get it all, it seems like the corrosion keeps growing with time, much like pinball machine collecting! Seriously though, make sure you get all the corrosion, or you will be visiting the issue again.

Keep us informed.

you can see in post #10 that the damage has gone way to the right hand side, also up to the 5101 and off to the left.

cleaning the damage will result in the lifting of the green silkscreen exposing the tin plating and maybe even to the copper depending on the severity.

it won't look pretty, but when neutralised properly and ideally sealed (imo), after component replacement, your board, when repaired should give you many years of ideally faultless performance.

that acid damage needs to be stopped.

Rickoshay - that's what happens after posting late at night. I forgot about that post. OP should also check all the pins in the connector on the right hand side of the MPU. It looks like they have been attacked, too.

https://pinside.com/pinball/forum/topic/stripping-battery-corrosion-with-a-strong-acid

Ciccoball - welcome back.

There are no reed switches on my machine. Regardless, I’ve attached pics of my right upper flipper wiring. Let me know if you need more.

image (resized).jpg

image (resized).jpg

image (resized).jpg

just noticing in the pics that the EOS switch looks to have standard switch contacts, not tungsten tipped contacts as it should, and something is amiss with the coil stop, it should be sitting flush against the coil base, it could be the pic but there appears to be quite a gap which would result in the coil moving, sliding forward and backwards?

I’ll check the coil tonight. The flipper seems to work fine, so I had not bothered to look at it.

I’ll also look at the EOS - this machine has had a rough previous life, so it doesn’t surprise me that some stuff is wrong.

Thanks for the heads up.

you're back Ciccoball and that's the main thing, hopefully not worse for wear.

you mention the machine working but without displays?

whilst it is booting up, the LED on the mpu going through its flash sequence, do you notice any of displays flickering an orange colour at all?

also assuming you have gas displays, or are they LED displays? can you post a pic please?

if you have gas displays they may not be getting the high voltage needed which derives from the rectifier board, fuse F2.......also you may have a solenoid driver board that is fused and that fuse is open.......best to check for the correct voltages.

Sorry @Billc479, just an observation is all

Ciccoball - If you have an orange glow at the bottom of the displays, you know they are getting the high voltage needed. The voltage may be off spec, but that's a different issue.

If you don't have a glow, check the fuse on the SDB and verify you have the correct voltages. If you have the correct voltages, you likely have a wiring issue. Bad voltages, you have a SDB problem.

Rikoshay is saying the same thing, and as he suggested, pics can help, but only if you want to get this completely operational. I suspect once you get the machine going, sometime in the future, the owners will decide they want to see scores.

Ciccoball - Yes, its a 4148. I could not get a good pic. Per the schematics, the switch diodes are supposed to be 1N4148, and the coil diodes are supposed to be 1N4004.

Like I mentioned to Rikoshay, this machine has had a hard past life. I'm trying to figure out what to do with the loose coil - the problem (I think) is the wrong coil stop is being used. It's a lot thinner compared to the left flipper.

I was referring to my SI. It’s working, but every time I go under the hood, I find another questionable repair.

We have that many machines because desire drives you to stupidity. There were several titles in a bunch of machines in an operators old barn that I wanted, the family said it was all or nothing, so I (we) got them all.

As far as your problem goes, check to make sure your end of stroke switch (Es?) are gapped correctly and making solid contact.

If you’re not sure, while flipper is fluttering, push a blade on the EOS switch and see if it stops.