Anyone hoping for Freefall plastics to get made?

https://pinside.com/pinball/forum/topic/stern-freefall-plastic-set-interest-check

You could try one of these:

https://pinside.com/pinball/forum/topic/new-6-inch-speakers-found

Was the 74L154 chip actually diagnosed as faulty? They rarely fail.

If all pop bumpers didn't work on the Harlem Globetrotters then the drop target resets wouldn't be working in your Stars.
Your solenoid driver board has double sided tracks making it more difficult to remove that chip without the right equipment/skills.
I'd suggest you open a tech support thread in the "Tech: Early solid state" subforum where we can help you diagnose the actual fault.

With the limited info, it looks like there's a breakdown in the signal on the solenoid driver board from pin 4 of connector J4 to leg 21 of the 74L154 chip. That signal is used when selecting chimes and the drop target reset solenoids.
It could be corrosion on that pin causing poor connectivity, a cracked solder joint on the back of the board where that pin is, damage to that trace signal running to the 74L154 or the 74L154 chip itself. If you have a multi-meter or logic probe we can further diagnose it but it's better done in the tech subforum if you want to follow up.

vpforums.org

Flipper coils are listed in the manual:
Playfield: J-25-475/34-4500
Backbox: J-25-600/34-4500

See here:
https://pinside.com/pinball/forum/topic/catacomb-club/page/2#post-2484855
https://pinside.com/pinball/forum/topic/catacomb-club/page/9#post-4494769

You'll find pictures in the Catacomb club thread including measurements for making one up.
[Edit] found some links:

https://pinside.com/pinball/forum/topic/catacomb-club/page/3#post-2593644
https://pinside.com/pinball/forum/topic/catacomb-club/page/3#post-2612565
https://pinside.com/pinball/forum/topic/catacomb-club/page/3#post-2612568

Trident came out before Hot Hand.
The Trident I had as a teen had the earlier screw studs mounting lockdown bar.
I think the lockdown bar changed during Hot Hand production?? My Hot Hand also has the screw stud lockdown bar (I seem to remember adjusting the screws about a year ago to get the lockdown bar to fit more snuggly).

[Edit] Trident lockdown bar receiver shows it needs the earlier screw stud mounting lockdown bar.
https://www.ipdb.org/showpic.pl?id=6443&picno=70571&zoom=1

Hot Hand showing it has the later lockdown bar receiver for the metal slot latch mounting lockdown bar.
https://www.ipdb.org/showpic.pl?id=1244&picno=6106&zoom=1

I suggest you open a tech support thread in the Early Solid State Tech sub-forum:
https://pinside.com/pinball/forum/forum/tech-early-80s-solid-state

Post pictures of how your transformer is wired and the three connectors that are plugged onto the rectifier board clearly showing the wire colors/positions.

The inline EMI filter is before fuse F6 so that fuse doesn't protect against a filter fault. A problem with that filter will hopefully trip a fuse in your house fuse box.

Yeah, transformer upgraded for higher solenoid current. You might notice most if not all MPU200 games have stronger flippers compared to the MPU100 games.
Most MPU100 games had 25-500/34-5050 flipper coils while the MPU200 games used 25-475/34-4500. Galaxy even lists 25-450/34-4500
Plus a number of MPU200 games had 4 flippers.

Is this a scratch build from a Catacomb playfield only? If yes, what are you doing for the head lightboard with the bagatelle artwork?

A little info here:

https://pinside.com/pinball/forum/topic/looking-for-part-for-post-sleeve-on-stern-dracula#post-3920288

https://images.pinside.com/0/99/93/09993d95a26998c7e91b95a55a324f51a2f5e5bb.jpeg
https://images.pinside.com/3/77/c5/377c5a6e79d937ff6328c0a36dc3d2cd69903c2e.jpeg

The "greatest" inserts on Ali are the very first lamps to be refreshed during the zero crossing routine. If on Dragon Fist you're talking about the 1000-8000 blue bonus inserts then same story. The SCRs driving those LEDs will find it most difficult to latch since the DC voltage is at the lowest point in the lamp refresh cycle and the current isn't yet at the right level for the SCR to latch in certain conditions. The types of LEDs used will probably be a factor but lower value resistors may likely be needed on those first lamp outputs in order to draw more current to help the SCRs latch.

As mentioned in my previous post, the blue bonus lamps are the first lamps to be refreshed during the zero crossing service routine - they are the ones most likely to suffer from flickering. Your using 4-SMD LEDs which draw more current than the single/twin SMD LEDs others are using. This results in more current through the SCRs allowing them to better reach latch current hold threshold.
Once you get the game working again it might be interesting to swap some of those blue 4-SMD LEDs particularly at 1k - 4k bonus to low cost non SMDs or single SMD and see what happens.

Your feature lamp voltage maybe a bit higher than others possibly due to the way your transformer is tapped resulting in slightly increased current draw.

You might be lucky that the batch/manufacturer of SCRs on your lamp driver board have lower than normal hold latch current characteristics. Spec for the 2N5060 and MCR106 SCRS state that holding current is 5ma "Max" meaning the worst case SCRs need to see at least 5ma before latching. In other words you might have SCRs capable of latching at lower currents. This is why when some people swap SCRs it fixes their issue.

I just looked up your MPU board picture you previously posted and notice you have RA28G ROMs meanwhile RA32 are the version in the wild and what I've twice recently seen.

We need you to get your ROMs dumped! They might be special with other differences!

FYI, Alltek is running Catacomb code matching the RA32 code.

Potentially yes. Looks like the German Stern ROM list for Catacomb may have started at version 25 - see page 3 of the below pdf.

It would be great if they could be dumped and the code preserved for the community.

Stern_ROM_list.pdf

Did the old fuse blow violently or was it just open circuit? Got a picture?
Do you have LED displays?

The question is whether there's other differences in your version.

It looks like it was a new fuse that blew so it had already been recently replaced?
Suspect it will probably happen again till the cause is found.

Measure the voltage at test point TP3 on the solenoid driver board. If you don't read 5 volts, you've lost voltage to the solenoid logic and predriver circuit on the solenoid driver board. Usually happens due to a bad connection on the 5 volt loop wire at connector J3 that runs from pin 13 to 25.
See the section from the solenoid driver board schematic below:

SDB_TP3 (resized).jpg

The transistor usually only blows when there's a problem with the diode on the coil preventing the back EMF being blocked, otherwise most other issues should cause the solenoid fuse under the playfield to blow, not the transistor. Check that fuse and make sure someone hasn't overfused it. Should be a 1 amp slow blow. Banded side of the coil diode should be on the yellow wire. Measure the DC resistance of that coil, it should probably be in the 9 - 10 ohm range.

As djblouw and chuckwurt showed/mentioned, that extra switch is for activating the upper left flipper.
It looks like somebody's bypassed that second switch so the upper flipper activates the same time as the lower flipper. The consequence is the left flippers will be weaker than normal because there's more current strain on the transformer the moment you flip.
Those flipper mech switches should be setup so the EOS switch opens first, then the secondary switch closes to activate the upper flipper.

Looks like I made a boo boo, it appears the boards I dumped had RA22 ROMs.

Looks like I made a boo boo, it appears the boards I dumped had RA22 ROMs and the typo was on my side.

It's the red high voltage wire going to pin 1 at the displays. Fuse the wire before the first display the wire connects to which is probably the player 1 display.

Love my Hot Hand..

There's actually two unpopulated switches in the switch matrix that spot the Ace. One scores 500 points, the other scores endlessly like the upper pockets.
Makes me wonder if that was the original intention of the white left standup near the spinner. Or maybe the ROMs were designed with a secondary layout/game in mind like Stern did with other MPU-100 games.

I intend to make it harder, getting bonus multipliers is too easy

Yes, making suites will increment the bonus multiplier. Plus changing the below mentioned by Whridlsoncestood so when you complete the grid, it immediately switches to super jackpot bonus so you can start filling the grid again. Right now it becomes a dead end on the current ball in play.

Are you considering rewiring one of the Hot Hand playfield switches to spot the Ace?

Agreed, it would be too easy otherwise

That was me. I'll be implementing it with other features after I'm done with some current projects.

Don't think that's rust, it's the color plating (copper tone) they used on that bracket. I've seen it before. Wait for someone else to chime in and confirm before you chemically strip it.

Make sure the wire that goes to the mains F6 fuse on the rectifier board is the one that's connected to Active (hot) pin on your power point plug.

Getting hard to find now.
You're looking for 25k ohm, 500mW logarithmic (audio taper) potentiometers.
None of the big electronic guys have them anymore.

You could try one of these - probably worth getting a suitable knob for it too:

ebay.com link: Alpha Potentiometer A25K Audio Taper Pot

Confirm with them that you're getting "A25k" pots which are logarithmic, and not "B25k" which are linear. You don't want linear because the volume wont adjust proportionately.

No, that potentiometer is for Ballys.
Clasic Sterns require a different pot. Look 9 posts up at post #3526 and #3527

Yes, like woody76 said, you can use alcohol to clean it.
I actually open them up to clean them and also retension the wipers while I'm there.

When setting the EOS switch gap you should do it by pushing the metal plunger into the coil, not by turning the crank - i.e. simulate the actual solenoid behavior. Otherwise your setting doesn't take into account any slack in the mechanism.

Not sure if this helps - from the Stern parts catalog. The MPU200 part number doesn't match what you've listed.

Stern_LockdownBar_79.jpg

Any reason the seller can't just send you pictures to see if they have the MPU100 stud pins?

The 1980 Williams parts catalog shows some switches with one of the contact rivets "upside down". Something tells me it's not a production mistake, it's by design.

Williams_Parts_Catalogue_1980_Switches.pdf

I don't dispute some accelerated wear, but there's no way they'd do it without a reason. Maybe the two flat surfaces swiping can cause multiple make/breaks when the switch gets a little dirty, where the rivet point is less likely.

Maybe we should ask BigAl56 if he's got any insight into the switches.

The gold contact switches in the 1981 Stern parts catalog all have one contact backwards.

Stern_Parts_Catalog_switches1.jpg
Stern_Parts_Catalog_switches2.jpg

It's on PinWiki:
https://www.pinwiki.com/wiki/index.php?title=Bally/Stern#Parts_Catalogs
Switches are on PDF page 37 of 56; the video game stuff is in the beginning of that catalog.

I like to think a dead bounce is also better off a flipper bat resting on the pin.

The pin might also partially act as Sterns version of a Bally/Williams snubber wire..

Yes. People make the mistake of aligning the flippers to be straight with the flipper return lane guides. It makes the flippers centre of the playfield centric where there's nothing to shoot for. It might be right for DMD games but not for these Sterns.

I'd be dubious about that info - how were operators around the world supposed to align the flippers without this special jig when the pins ideally served the purpose?
All the Sterns I remember playing in the early 80's had the flipper bats against the pins.

Bally never used those pins on their early solid state games.

Heh, well I'm opposite. To me they don't look right when the flippers are straight with the return lanes and they sure don't play as well as factory "droop".

I think Williams from that era aligned their flippers to be straight with the return lane guides. Been too long since I've been near one, maybe someone else can comment.

That would be Bally
Medusa's a perfect example with the flipper inserts under the flippers:

IMG_0013a.jpg

Wowee

It must be something with the infrared LEDs on the camera. Can you see the Catacomb image when looking directly at the cabinet (not looking at the camera image) when the camera's pointing at it?

Two digits are for the year of manufacture, the other two I think are week number of the year. Lots of semiconductors have this 4 digit date coding system.

-7918 manufactured 1979, the 18th week
-8067 manufactured 1980, you first mentioned this was 8027 so I presume it's a typo
-8027 manufactured 1980, the 27th week
-8014 manufactured 1980, the 14th week
-7932 manufactured 1979, the 32nd week, just before Meteor came out so it could be a 16B-6 made in readiness for Meteor.

Normally I would say to check the manual, but in this case the online QuickSilver manual incorrectly has the 16B-3 transformer :-/

From another MPU-200 game manual: Your transformer picture above shows it's wired for 240V

Transformer_16B-6(1).png

They're probably 1N4148 diodes.

Nominal line voltage in the US and Canada is 120 volts +/- 5%.

120V into a 115V tapped transformer means the transformer is outputting marginally higher voltages. This means the game is dissipating a little more power for no good reason. A little more stress on power connectors and components. Will it work if you leave it? sure.

If as you said you want this build setup properly then change the transformer to 120V input.
Remove the yellow wire from lug 9 and cut the bridge wire between lugs 9 and 11.
Solder a heavy bridge wire across lugs 5 and 7 and solder the yellow wire to lug 5.

The change in line voltage specification to nominal 120V occurred in the 70's. The rollout didn't happen overnight.
Product manufacturers were still building to the old 115V spec and even for some time onwards.

For nearly 40 years the nominal line voltage in the US is and has been 120V +/- 5%.

See here under "USA Standard Residential Voltage"
https://www.w8ji.com/power_line_voltage.htm

Yes it's oriented correctly.

If it's green gunk from wire, try hot water to remove it.
But that resistor looks like it has battery corrosion, better to replace it - otherwise remove it, scrape all the corrosion off it with a blade to expose copper, retin the legs with solder and reinstall.

What exactly is the problem you're having and which game?
Which lamps aren't working properly and in what way?

There was a little discussion in the Stern Magic club thread about different plastic sets:
https://pinside.com/pinball/forum/topic/classic-stern-magic-club-all-are-welcome/page/2#post-6033908

First suspect is the F4 solenoid fuse on the rectifier board.

What's switch test mode telling you?

Don't worry about resoldering those other switches yet, just go into switch test mode first.

That's solenoid test mode. You need to press the self test button one more time to get to switch test mode. As slochar mentioned, if you have his Big Game ROM use the switch test mode from that which will give you *much* more detail about closed switches. The factory switch test mode is useful but does have limitations as he mentioned.

Q15 Q19 drives the coin lockout coil so the game will accept coins. This is normal. This coil de-activates when maximum credits are reached/game is off so any coins inserted get rejected.

[Edit] Q15 is for the flipper enable relay on the solenoid driver board.

The MPU board signals controlling the switch matrix are the same signals that control lamp selection. So the problems are related.

emsrph and cadmium were right to suggest it could be coin door related (because of a stuck coin switch), but you've discounted that.
It's sounding like you have a switch matrix wire shorted to a lamp somewhere.

BTW, when and how did this problem begin to happen?

The issue shouldn't have any relation to the lamp driver board or connections to/from it. The issue in your case is the 5.4VDC feature lamp power running on the playfield that's connected to the braid/base of all the feature lamp sockets has a short to a switch.

By my deductions, the strobe zero "ST0" white-red switch wire is shorted to a feature lamp somewhere. But in saying this you should be seeing the same behavior with the right spinner activating the right pop bumper.

Anyway, closely inspect all the playfield switches on the ST0, ST1 and I3 return wires for now, paying primary attention to the switches on ST0.

Yes you can install that Big Game MPU board/software in your Star Gazer, but make sure you disconnect the small J4 connector from the solenoid driver board. You don't want Big Game software activating the wrong coils for the wrong length of time.

10 points to the first person that spots the problem. Hint look at the T-Nuts...
.

StarGazer_Short_To_6VDC.jpg

Ding ding ding!
That T-Nut is electrically connected to the spinners leaf switch through the whole spinner assembly.

Are all switches on those three "Ix" rows not working?
Note if the game senses any switches that are stuck closed it will ignore them until they open again, otherwise they could cause endless scoring.
Switch test mode is your friend here.

Switch test mode.. Let the game tell you what it's seeing in response to all the switches. You may have some open circuits in the wiring but you also may have some shorted switches which switch test mode will tell you about where game play mode won't.

A scan of the Stern parts catalog is also on PinWiki:
https://www.pinwiki.com/wiki/index.php?title=Bally/Stern#Parts_Catalogs

Please post some clear pictures of the slingshot switches including side on showing how they're stacked. Since both slingshot switches are showing as closed I suspect they've been incorrectly connected.

My favourite family
Glad you worked it out!

The PinMAME ROMsets on IPDB are named so PinMAME can use them directly. There's otherwise no difference between them and the other ROMs. They will work on real hardware, i.e. the 7-digit bootleg is not specifically for PinMAME.

Which switch matrix connector(s) are you disconnecting to make it work?

If you've got a logic probe:
+ Reconnect the switch matrix.
+ Disconnect J5 from the solenoid driver board to disconnect the right drop target reset coil from activating (so it doesn't blow the fuse)
+ Probe pin 20 of the U2 decoder chip on the solenoid driver board around the time/event that usually causes the playfield fuse to blow and report the logic level.

I don't have enough diagnostic details yet to answer that - my previous post is hopefully a start to get there.
May I suggest you open a tech thread on it since your problem is likely to be something specific to your machine.
A couple of pictures of the coil/switches in question won't hurt.
Anyway I've got to head off now so won't be able to respond til later.

No.
Those voltages are in range.

There was discussion about this in one of Pinitechs display threads a few years ago. Some games shipped with a 7-digit display in the 5th position.
Notice how the credit window is wider than the ball in play window? That way it can support both 6 and 7 digit displays. You will need to move the digit enable signals on the connector to get the digits to line up with 6-digit displays.
i.e. at the credit/ball in play display connector:
- Take the yellow wire out of pin 6
- Move the grey wire from pin 7 to pin 6
- Move the white wire from pin 8 to pin 7
- Put the yellow wire at pin 8 for safe keeping.

Cheers, and another Stern error in the schematics.

Found the original Pinitech discussion:
https://pinside.com/pinball/forum/topic/credit-display-for-stern-star-gazer-6-digit-or-7-digit

The Weebly MPU board has jumpers to configure the clock speed. How have you got them set?

The SB300 sound board has it's own timer chip. I can't confirm but would be surprised if the CPU board clock speed had any effect.

Have you run the memory erase on the Alltek? Corrupt data in the NVRAM has been noted to cause different sounds on Meteor.
Also are you sure the issue isn't the ribbon cable or the sound board itself?

I see.. While the timer chip has its own dedicated onboard clock, it can be overridden by the CPU clock.

Part of the problem is people like to fiddle with the sound board pots which throws the tones horribly out of tune with another. It's rather difficult to find youtube SB100 based game videos where the tones are in proper tune. It's made worse with how slow these games score compared to Trident/Hot Hand/Magic and speeding up the scoring code helps them feel more responsive and less painful.

The rev A SB100 board used in Lectronamo and Wild Fyre had the tones pitched high so the chime simulation tones were about the same frequency as real mechanical chimes. Personally I like the chime simulation.

Note: Lectronamo, Nugent, Wild Fyre and Dracula need DIP switch 23 set to ON when using any sound boards (factory or repro) that don't have the chime simulation otherwise they'll produce no sounds. If using a rev C1 sound board or @barakandl's repro, they will have the same bassier tones as delivered in Trident/Hot Hand/Magic.

The difference in solenoid power looks pretty obvious to me.

The solenoid voltage on these games is unfiltered DC. As a simple test, try a high current diode in series with the solenoid voltage to the playfield and put a capacitor on the other end to store energy.

Isn't DC solenoid power on Williams game of that era filtered?

The primary and some secondary windings will be thicker so it can deliver more current and hence the larger physical size. Anyone feel like measuring the transformer winding gauges between the -3 and -6 just before the lugs to compare?

Yes, Magic utilises all six sounds. The fifth sound is the "add bonus" sound effect.

The thickness of the metal E core is probably the same, hence the Y-axis is almost the same.

It's dependent on the type and number of flipper coils. Meteor and Ali had standard spec 25-500/34-4500 flipper coils. The upper coil on Meteor has a resistor in series to reduce current surge and power.
Galaxy had higher power flipper coils but only two of them.
Big Game had a mixture of standard and higher power flipper coils but there are four of them so potential for high current surge when all four flippers activate at the same time.

I just picked up a Seawitch this week and it's been fitted with four standard 25-500/34-4500 flipper coils. I've replaced the 7A slow blow fuse with a fast blow as a slow blow seems like overfusing to me.

Sorry, by "standard 25-500/34-4500 flipper coils", I meant common generic flipper coils. And power wise they're perfectly fine on this game.

It will be thicker gauge core wire on both the primary and solenoid windings.

You could try what frunch does and solder them on the back of the leaf:

https://pinside.com/pinball/forum/topic/building-re-building-leaf-switches

Yes, Bally did it on drop target banks with 6 or more targets: Someone installed a 27-2300 coil on your bank which is used on 5 drop target or less banks and it might not have been strong enough for that big bank so it might be the reason they doubled up the coils. The Nineball manual lists a 24-1600 coil for that assembly.

Drop_Target_Bank_Fathom.jpg
Drop_Target_Bank_EightBallDeluxe.jpg

Nope. But I should say if you're thinking of doing this don't use the super strength 24-1600 coils Stern used for this 8 bank. Use two of the weaker coils (26-1900 or 27-2300)

The picture djblouw posted above shows a Stern 27-2300 coil and a Bally ??? coil (which is unlikely to be a super strength unit).

You won't blow the transistor. The Cheetah manual actually specifies a 24-1600 coil for the 5 bank drop target assembly so you should be ok.

So what are you going to do since the assembly already has a Stern spec coil?
If you're staying with double coil, I would check your other Bally/Stern games to see if you can swap the 24-1400 out with a weaker drop target coil from another game.

Not really stress on the transistor, but you will likely prematurely blow the playfield fuse.
The lowest DC coil resistance this architecture uses on transistor driven coils is about 10.5 ohms and that's what the 24-1400 coils resistance is.

The 26-1900 coils are 22 ohms. Two in parallel equate to 11 ohms DC resistance
The 27-2300 coils are 32 ohms. Two in parallel equate to 16 ohms DC resistance.
Both of these setups are still in spec.
I would swap out the 24-1400 with one of the two coils mentioned from another game (preferably 5 bank if a game has a weaker coil) or buy a new coil or convert the bank back to single coil (I realise twin coils are better mechanically).

Check the five green spots in this picture - where there's switches in these positions they're likely to all be switch 19.

Wild Fyre (Stern 1978)_Sw19.jpg

Cosmic Princess!!

I've seen this elsewhere on non-pinball products, the paint on the screws is used to stop them loosening from vibration, kinda like surface loctite.

I've had a code fix for Cosmic Princess for some years to fix the spinner scoring bug. I'll be releasing it very soon with some other early Stern updates after I finish up on Stingrays code.

Whoa..
There's art on the left of that backglass picture that's flaked off so if the picture is the actual backglass for sale, it's rather used albeit rare.

Magic and Cosmic Princess do use the same ROMs. Magic doubles the drop target switches on the two outer drop targets so they score 1,000 points while the centre drop target scores 500 points. That's how they got away with a 3-bank drop target on Magic.

Trident code is about 98% the same, the difference is that Magic awards climbing points on drop target completion. Trident doesn't but awards them at the saucer instead while Magics saucer awards collect bonus.

I have code updates ready to release for these three games. Might upload this weekend..

I'm in the same boat and am in awe of what Dick has done, it's amazing and very clever indeed! But modern rules/games aren't my thing.
I actually did the Trident update before BSOS 2020 came about, but just never got around to releasing it. Like the Stingray update I'm working on now (nearly finished) you'll need to modify the MPU board for dual 2732 EPROMs to run the updated Trident code.
The key features is has are:

01. Freeplay support.
02. Millions scoring using real 7-Digit displays or virtually with existing 6-Digit displays.
03. Bonus multiplier option up to 14X.
04. Fast bonus countdown once option by pre-multiplying the bonus 1k step against the bonus multiplier.
05. Saucer big scores option up to 65,000 points.
06. Flipper return lane big scores option up to 20,000 points and resettable on entry.
07. Disable the upper slingshots from advancing bonus option.
08. Extra ball kept option when the ball in play is tilted.
09. Colored standup target special options to be open ended and/or lit after completing two times rather than one time.
10. Drop Target special added options to light on the 1st or 4th completion of the bank, and/or then every second bank completion.
11. Drop Target option to disable the drop target releases (always requires player to hit all five drop targets).
12. Show the Highest Game to Date at the start of the last ball.
13. Record Highest Game Credits to Date in Freeplay Credit Reset mode.
14. Show *every* closed switch in switch test mode.
15. Improved test mode/audit navigation.

Nugent shares the same ROM with Lectronamo.
Dracula shares the same ROM with Wild Fyre
Stingray shares the same ROM with Pinball
Cosmic Princess shares the same ROM with Magic
Hot Hand has some unused switches programmed so they may have either decided not to wire them, or the ROMs may have possibly been to support a different layout/game. Though MPU-200 was around the corner..

Alright, the code updates are up:

https://pinside.com/pinball/forum/topic/magic-stern-1979-software-update

https://pinside.com/pinball/forum/topic/cosmic-princess-stern-1979-software-update

https://pinside.com/pinball/forum/topic/trident-stern-1979-software-update

Any chance the EOS switch screws are too long and are digging/cutting into the flipper coil?
Have you tried moving the hold wires where they attach to the lugs to see if they've broken off there? Can you clearly see that the wire coating has been removed where they're soldered to the lugs - from the picture it looks like the left lug has a coated wire on the lug.

We really needed the multi-meter in view to see what it was indicating and what setting you had it on.

Nope.
Your EOS switch was not opening at the end of stroke causing the flipper thrust winding to hold the flipper up for extended periods with sustained high current through the thrust winding. So she got hot.
When adjusting the EOS switch gap, push the plunger into the coil so it's at end of stroke exactly as it really operates, don't rotate the flipper bat or crank to get it to full stroke since it doesn't take slack/wear in the mech into consideration.

4? No way! Let's go with:
5) long covid.

Nitro has them in stock:

https://nitropinball.com/products/homepin-bally-a2-power-transformer-module-as-2877-1-inc-tx122-125-as-2518-pcb-mounting-bracket-w-screws