(Topic ID: 252204)

Galaxy Stern zero AC voltage on TP4 (first pinball machine)-Update: working!


By 1stpingalaxy

8 months ago



Topic Stats

  • 27 posts
  • 10 Pinsiders participating
  • Latest reply 7 months ago by 1stpingalaxy
  • Topic is favorited by 3 Pinsiders

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  • Galaxy Stern Electronics, 1980

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#1 8 months ago

Hi! this is my first post, and my first pinball machine!

I bought it at an auction and was unable to look inside as they did not have a key -- I ended up paying $800 for it. I sort of lucked out as when I drilled the coin door lock there was $210 in quarters inside! (no silver unfortunately) The latest dated quarter was 1985, and the earliest was 1965.

Only one mouse nest, and other than a leaking battery it was in pretty good shape -- all the fuses tested good. someone had physically cut off the ground on the plug so I wired a new one in. Then I fixed the insulation that had been chewed off some wires by the mice. Then fired her up.

The feature lamps all work, as do the solenoids, and half of the 7 segment pinscore displays work so far. The audio also works. The machine is basically playable now.

Here is my problem, the general illumination (GI) does not work. I tested the rectifier test points and they all tested great except for TP4 which has zero AC voltage on it. The other DC test points are all within spec. Based on the info I can find the GI is powered by the 7.3VAC bus, and I'm at a loss what to do now to trace the issue any further. Does this mean my transformer is bad? I would think not since its clearly providing the proper AC voltages to the BRs for the other buses.

I have already pulled the J1 and J3 plugs and the TP4 remains at zero voltage, so I think that means there isn't a short (but could be mistaken). What should my next steps be?

Thanks!
IMG_20190923_184107 (resized).jpgauction-listing (resized).jpgcoinsinside (resized).jpgcontrolboards (resized).jpginsdie-lower (resized).jpgmouse-wires-repaired (resized).jpgquarters (resized).jpg

#2 8 months ago

Congratulations on your first pin and welcome to Pinside.
http://www.pinwiki.com/wiki/index.php?title=Bally/Stern#-18.2C_Stern_Rectifier_boards

Dig into your schematic and figure out what feeds TP4. Watch for bad fuse clips and burnt connectors.

#3 8 months ago

I'd start looking for a broken wire between the transformer and rectifier board--there is evidence of damage in that area. It's really not common to have a transformer fail, so I'd start there. Note that the wires from the transformer solder directly onto the back of the rectifier board.

#4 8 months ago

I'm having trouble understanding based on the schematic here (https://www.ipdb.org/files/980/Stern_1980_Galaxy_Selected_Schematics_and_Wiring_Diagrams.pdf) what leads are what on the transformer?

If I could figure out which pairs to test for the base voltages, then I could narrow it down a bit (i.e. if I can find the proper voltage coming from the transformer then i can trace it to the rectifier). Would also make it easier to figure out what wires to test for continuity between the rectifier and the transformer. Based on information here (http://techniek.flipperwinkel.nl/ballyss/rep/index1.htm) it appears the transformer should output the following AC voltages, which then get rectified into DC voltages:

7.8AC --> 5.4VDC
12 AC --> 11.9VDC
49 AC --> 43VDC
173 AC --> 230VDC
7.3 AC --> Stays the same at 7.3AC

Can anybody point to what points/wires/colors are what voltage pairs off the transformer?

Thanks!

transformer (resized).jpg
#5 8 months ago
Quoted from 1stpingalaxy:

Hi! this is my first post, and my first pinball machine!
I bought it at an auction and was unable to look inside as they did not have a key -- I ended up paying $800 for it. I sort of lucked out as when I drilled the coin door lock there was $210 in quarters inside! (no silver unfortunately) The latest dated quarter was 1985, and the earliest was 1965.
Only one mouse nest, and other than a leaking battery it was in pretty good shape -- all the fuses tested good. someone had physically cut off the ground on the plug so I wired a new one in. Then I fixed the insulation that had been chewed off some wires by the mice. Then fired her up.
The feature lamps all work, as do the solenoids, and half of the 7 segment pinscore displays work so far. The audio also works. The machine is basically playable now.
Here is my problem, the general illumination (GI) does not work. I tested the rectifier test points and they all tested great except for TP4 which has zero AC voltage on it. The other DC test points are all within spec. Based on the info I can find the GI is powered by the 7.3VAC bus, and I'm at a loss what to do now to trace the issue any further. Does this mean my transformer is bad? I would think not since its clearly providing the proper AC voltages to the BRs for the other buses.
I have already pulled the J1 and J3 plugs and the TP4 remains at zero voltage, so I think that means there isn't a short (but could be mistaken). What should my next steps be?
Thanks![quoted image][quoted image][quoted image][quoted image][quoted image][quoted image][quoted image]

It’s in nice condition, it looks! The leaky battery might have severed a trace? It’s at the bottom so it’s unlikely, that’s just my guess

It’s cool how nice and clean everything in the back is since it’s never been disturbed.

#6 8 months ago
Quoted from 1stpingalaxy:

Can anybody point to what points/wires/colors are what voltage pairs off the transformer?

The Galaxy transformer/rectifier board schematic is below (click to zoom in).
The transformer lugs are numbered - it might be a bit difficult for you to see some of the numbers since mice ate some of the transformer covering.
Anyway for the G.I. power wiring:
Transformer lug 17 has a blue wire that goes to the rectifier board and as is soldered at point E7
Transformer lug 18 has a black wire that goes to the rectifier board and as is soldered at point E8

You should measure 7.3VAC between lugs 17 and 18 at the transformer and also across points E7 and E8 on the rectifier board.
.

Galaxy_Power_Module.jpg

#7 8 months ago

Thank you for all the help guys! I was able to test the correct points off the transformer and the proper 7.3VAC voltage is there! Now I just need to trace the wires to the rectifier board and look for a bad connection somewhere I think.

Since all the other AC voltages must be there due to the proper DC outputs existing at the test points, my assumption is this is probably just a connection problem somewhere on the back of the rectifier board, since nothing fancy is done to this voltage as it passes through the board.

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#8 8 months ago

The problem could be in that GI blinking relay. Looks like the blue wire from the transformer goes to that relay then to the rectifier board. I don't know if the relay is normally on lamps or normally off lamps, but if the relay is not working properly it could be permanently interrupting the 7vac getting to the rectifier board / gi lamps. Without looking at the schematics 43vdc and a continuous solenoid driver circuit likely clicks the relay off and on.

Make sure mouser did not nibble on the blue wire going to the rectifier board too.

#9 8 months ago
Quoted from barakandl:

The problem could be in that GI blinking relay. Looks like the blue wire from the transformer goes to that relay then to the rectifier board. I don't know if the relay is normally on lamps or normally off lamps, but if the relay is not working properly it could be permanently interrupting the 7vac getting to the rectifier board / gi lamps. Without looking at the schematics 43vdc and a continuous solenoid driver circuit likely clicks the relay off and on.
Make sure mouser did not nibble on the blue wire going to the rectifier board too.

Thanks. I'll check that too. I hear the relay clicking when the machine is doing its 'dim the lights' thing but of course theres no effect since there is no power to the GI bus. I'm not sure if that means its good or bad. If I had to replace it, do you happen to know what relay I would use? I saw this one mentioned a few places,but i'm not sure its correct. Does the DC in this relay mean the solenoid driver sends its 40V DC signal to the relay to interrupt the 7VAC circuit? https://www.greatplainselectronics.com/proddetail.asp?prod=LB2-48DS&cat=143

#10 8 months ago
Quoted from 1stpingalaxy:

Thanks. I'll check that too. I hear the relay clicking when the machine is doing its 'dim the lights' thing but of course theres no effect since there is no power to the GI bus. I'm not sure if that means its good or bad. If I had to replace it, do you happen to know what relay I would use? I saw this one mentioned a few places,but i'm not sure its correct. Does the DC in this relay mean the solenoid driver sends its 40V DC signal to the relay to interrupt the 7VAC circuit? https://www.greatplainselectronics.com/proddetail.asp?prod=LB2-48DS&cat=143

There is a solenoid coil inside the relay box that moves relay switch blades around. Voltage is applied to the coil inside the relay box and then a transistor on the driver board provides the path to ground to make the coil pull in and move the switch blades in the relay box. I don't know 100% for sure but I imagine this relay is going to be a using a 48v rated coil to be powered by the 43v in the game. Its probably the exact same relay that is used on the driver board for the flipper relay. If so the one you linked is probably right but double check.

#11 8 months ago

Found it! Thank you guys! I traced the leads from the transformer into the relay, bridged past it, and now I've got GI! I don't think this poses any risk since the current is just going to the rectifier board where it passes through the F5 20A Fuse. It was stupid of me to consider the relay 'good' just cuz I could hear it clicking when called upon, as clearly it was cutting off the AC current entirely.

Unless there are any other suggestions, I'm going to order the relay I listed above to replace it.

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#12 8 months ago
Quoted from 1stpingalaxy:

Found it! Thank you guys! I traced the leads from the transformer into the relay, bridged past it, and now I've got GI! I don't think this poses any risk since the current is just going to the rectifier board where it passes through the F5 20A Fuse. It was stupid of me to consider the relay 'good' just cuz I could hear it clicking when called upon, as clearly it was cutting off the AC current entirely.
Unless there are any other suggestions, I'm going to order the relay I listed above to replace it.[quoted image][quoted image]

Nice job finding it.

Relays contacts might be welded together, broken or burned. Maybe you can peak inside the case and see whats going on but probably not worth trying to repair the one you got. A new relay will get you going. Consider replacing the relay socket too or just soldering wires right to the relay terminal.

The gator clips I wouldn't use for an extended period as I don't think they can pass 10-20 amp. Could snip loose the two blue wires and wire nut them together until you get the replacement in.

#13 8 months ago

I went ahead and tied the two wires together and dropped a bit of solder on them for now. And I ordered a couple new relays from Great Plains to replace the one that blew.

While I was replacing bulbs, I would work on some off then turn it back on again. I started to notice an intermittent dimming of the lights. I'm not sure what exactly that means. I was mostly working on the feature lights (the DC blinkers). I hope it doesn't mean I have another problem to deal with. I have a bad feeling it might mean I should probably replace the entire rectifier PSU to be on the safe side, which sounds like a bit of a project.

The GI lights are separate from the feature lights, so I would think it wouldn't affect it -- but perhaps it means my entire psu board is going bad.

Still, it seems like I made progress tonight, but naturally there had to be a set back as well.

#14 8 months ago

Looks like a really nice game. Take care of it and it will last another 30 years. A few comments and suggestions – First, get that battery off the MPU. It’s already corroding. Replace it with a remote battery or NVRAM. barakandl (nvram.weebly.com) has nice NVRAM.

Since the previous tenants dined on the wiring, transformer, and other stuff, closely inspect everything. Make sure the wiring is properly insulated. I don’t think the electrical tape is going to cut it. Heat shrink tubing is best. I have used liquid electrical tape for small areas but you need to give it several coats. See this thread:

https://pinside.com/pinball/forum/topic/top-tip-%e2%80%93-liquid-electrical-tape

Next tip – when you lean the playfield back into the backbox you might want to lay a towel over the backbox to prevent scratching any surface.

IMG_1188 (resized).JPG

Also be sure all your connections are good. You may want to read this thread:

https://pinside.com/pinball/forum/topic/advise-for-early-solid-state-owners

Good luck with your new game.

#15 8 months ago

Thanks. I'm going to go through the connectors tonight. I went ahead and cut the AC voltage I fixed earlier to try and 'get back to where I started' but the dimming issue is still there, and the machine is rebooting on its own sometimes (with an occasional solenoid firing randomly).

I did remove the corroded battery earlier, it was actually the first thing I did before I moved onto anything else. There wasn't any real visible damage thankfully.

I'm not really sure where to start here but I'll probably start by pulling the J1-J3 connectors and testing voltages with various areas isolated first. Then perhaps I can narrow down whats causing the dimming/rebooting.

I was only replacing feature bulbs last night, but perhaps I introduced a short somewhere in the process. I was extra careful, but anything is possible. The fact that the bulb wire has to be unscrewed from the back of the playfield to change them certainly increases the odds of something getting crossed along the way.

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#16 8 months ago
Quoted from 1stpingalaxy:

Thanks. I'm going to go through the connectors tonight. I went ahead and cut the AC voltage I fixed earlier to try and 'get back to where I started' but the dimming issue is still there, and the machine is rebooting on its own sometimes (with an occasional solenoid firing randomly).
I did remove the corroded battery earlier, it was actually the first thing I did before I moved onto anything else. There wasn't any real visible damage thankfully.
I'm not really sure where to start here but I'll probably start by pulling the J1-J3 connectors and testing voltages with various areas isolated first. Then perhaps I can narrow down whats causing the dimming/rebooting.
I was only replacing feature bulbs last night, but perhaps I introduced a short somewhere in the process. I was extra careful, but anything is possible. The fact that the bulb wire has to be unscrewed from the back of the playfield to change them certainly increases the odds of something getting crossed along the way.[quoted image]

MPU looks surprisingly clean. Seems like 90% of originals you come across have battery damage. You can gently flex on the MPU board and it's chips to see if a flaky connection is causing the reset. The 12v regulator has an isolated ground return between the rectifier board and the solenoid driver board. Its common to see that connections toasted at either/both ends and can cause resets if the voltage regulator input drops below the breakdown point. Its an orange wire. Check out the ground modifications to the driver board. Its basically combine all the grounds together at the driver board. They should be pictured with more info on pinwiki and other guides.

Flippers are going to cause some dimming of the lamps. Its unavoidable to some extent but having the rectifier board connections in good shape will help.

If the lamps stay dim while a flipper is held the end of stroke switch on the flipper mech needs adjust to open up at the full stroke of the flipper.

#17 8 months ago

Well, I've been playing pinball the last 2 days. Its been awesome! Figured out the problem was a power delivery issue coming from outside the cabinet, so no internal issues at all.

Installed fresh rubber, and replaced the lights that needed it. Have almost every single light working, the few that I don't have working I may just need to replace the sockets themselves.

I also 3d printed some replacement parts for some that were broken and I think they came out really great. They don't really take direct hits from the balls as the star posts with fresh rubber do instead so they should be strong enough. At this point the next big fixes on my plate (until something else breaks) is replacing the dimming relay, and trying to get all the old pinscore displays to work (I've got 3/5 working so far). I'm going to meticulously go through all the pins on them and see if they need to be re-soldered.

I can't thank you guys enough for all the help to get this far. Its been a great first week of pinball restoration here.

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1 week later
#18 7 months ago

Ah, I'm glad it went to a good home! Sorry but I was the one driving up the bid on that, I really wanted it! You wanted it a bit more though. Enjoy!

#19 7 months ago

Glad you got it going. Also HOLY SHIT on the coin bucket!!!!

I miss mine. A simple, fun, really cool looking pin by Mr. Williams himself.

Thanks
Blake

#20 7 months ago

@jahkub no worries! did you win the harlem globetrotters, dolly parton, and mata hari pins? I think I know who won the Playboy one.

And some more pics of the entire thing together. It plays FANTASTIC and looks GREAT. Already ran through probably 250 credits worth of games the last week or so.

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#21 7 months ago
Quoted from 1stpingalaxy:

@jahkub no worries! did you win the harlem globetrotters, dolly parton, and mata hari pins? I think I know who won the Playboy one.
And some more pics of the entire thing together. It plays FANTASTIC and looks GREAT. Already ran through probably 250 credits worth of games the last week or so.[quoted image][quoted image]

If you haven’t yet, I’d recommend replacing the ball. It’s probably never been replaced since it was unboxed! A pack of pinballs is cheap and a new ball will keep the playfield looking beautiful!
Old pinballs get divots and scratches and effectively act like Sandpaper on the playfield being slapped around at high speed.

#22 7 months ago
Quoted from Isochronic_Frost:

If you haven’t yet, I’d recommend replacing the ball. It’s probably never been replaced since it was unboxed! A pack of pinballs is cheap and a new ball will keep the playfield looking beautiful!
Old pinballs get divots and scratches and effectively act like Sandpaper on the playfield being slapped around at high speed.

I bought a few brand new ones thanks! The old one had a rusty spot on it and I didn't trust it not to screw things up. So far I've poured about $200 into this machine to get it where it is today. Admittedly some of that money was wasted as I bought a bunch of LEDs only to realize I didn't really like how bright they were, and instead only used them in the pop bumpers.

But I'm figuring they'll come in handy with the next pin I get

I forgot to mention, the GI relay was the main source of problems, and once I replaced it with a fresh one the GI now does the dimming effect it was supposed to. Basically, its running 100% now with the exception of two screens I haven't gotten to work. I'm going to try and fix them but I'm hard pressed to want to spend hundreds more on replacements right now.

#23 7 months ago

I did get mata and Harlem, here they are cleaned up and with pf protectors on them.

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#24 7 months ago
Quoted from Jahkub:

I did get mata and Harlem, here they are cleaned up and with pf protectors on them.[quoted image][quoted image]

OH man those look GREAT!!! Were they in pretty decent shape when you got them home? Any boards need to be replaced? Or just normal cleaning and maintenance items?

#25 7 months ago
Quoted from 1stpingalaxy:

OH man those look GREAT!!! Were they in pretty decent shape when you got them home? Any boards need to be replaced? Or just normal cleaning and maintenance items?

The mata hari mpu was pretty trashed so I bought an alltek. Harlem's was salvageable but needs lamp board work. I'm in the process of re pinning all the boards and re crimping all the connections, that alone fixes many issues. I replaced the big SDB caps and did the grounding/bulletproofing hacks to a few things. I had a suggestion to put down playfield protectors in order to level the inserts and such so I bit the bullet and I'm not disappointed. The games play fast and smoothly now.

#26 7 months ago

Great work 3d printing the lane guides but those are actually available new if you want to replace them.

#27 7 months ago
Quoted from slochar:

Great work 3d printing the lane guides but those are actually available new if you want to replace them.

Thanks. I don't think I'm going to replace them with new ones, I wasn't able to find any at the time, and honestly these look really good to me and are completely functional. I think they'll last too, as they don't take much direct abuse from the ball since they are only guides.

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