Star Gazer Rising!

I was lucky (?) enough to pick up a Star Gazer last week! I played a mint example of this game at the Vancouver FlipOut Pinball Expo this fall and when one came up locally I somewhat irrationally jumped at it. Wasn't planning on adding another game but how often does a Star Gazer come around? Answer: Not very often.

Overall the condition is, er, "interesting":

- Game is not working, previous owner had it for maybe 6 months and was unable to get it to work while he owned it.
- Cabinet is pretty clean, with a few unfortunate dings esp. in the front, and some fairly bad paint touchups.
- Backglass paint is fully separating from the glass and has been triple-thicked or something to keep it on the glass. Considering how much is bubbling it actually looks pretty decent, I've seen far worse. Unfortunately they didn't cover the score windows before spraying so I'll have to do something about that.
- Playfield is really planked and lots of smallish wear spots throughout. Some really clumsy paint touchups throughout as well. Looks okayish though, and the inserts are still quite level. Has the wrong pop bumper caps installed, I did receive 2 originals with the game, missing one. Two of the spinners are not original.
- Backbox boards look really clean, no hacks, except for what appears to be some slight battery leakage damage to the MPU.
- Inside the cabinet is near mint. New RottenDog rectifier board came with it, but not connected, totally missing the J3 plug, just loose wires.

As you can see the game is a bit of a project, and I've already got "too many" of those!

My short-term goal is to do a bit of minor cleanup and get it playing so I can add it to my lineup while I work on my other projects.
Long-term, I'm in the queue for a new PF from greatwichjohn and will also be getting one of his beautiful backglasses for it as well. So a complete playfield restore is in the cards eventually.

I don't have much experience with classic Sterns/Ballys so I'll post the issues with the game as I encounter them here and you can all help me solve them. Let's get this Star Gazer playing again!

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The most obvious problem with the game that I noticed immediately was the missing J3 plug for the rectifier board.

While inspecting the Rottendog rectifier I noticed that the solder job on it was pretty poor so I went ahead and re-confirmed that the correct wires were going to all the right places on the board and re-soldered each one. This was a bit tricky since 2 of the wires were not colored as indicated in the PinWiki article I was using as a reference.

Before:
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After:
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The following resources were invaluable in identifying the correct pin order for the J3 plug, and transformer-rectifier wiring:
- http://pinwiki.com/wiki/index.php?title=Bally/Stern#Rectifier_Boards
- http://www.techniek.flipperwinkel.nl/ballyss/rep/index1.htm

I also downloaded the schematics for the RottenDog rectifier board from their website.

...and the power plug had no ground pin, so I fixed that immediately as well.

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--- (Bear with me while I catch you up to current events) ---

So, with J3 and J2 now connected to the Rectifier board it's time to fire it up!

With visions of being one step away from a fully working game I flick the power switch...

...and NOTHING. No action at all on the MPU, the LED isn't lit at all.

Checking the test points on the Solenoid Driver Board (SDB) shows 0.4V at the 5V test points. Uh-oh.
Time to disconnect everything from the SDB but J3.

Re-checked the rectifier tests points - good.
Checked the J3 pins on the rectifier board - good.
Checked the J3 connector at the back of the #8 pin, 12V - good.

At this point I need schematics as my SG manual didn't include any. Nothing for SG on IPDB.org, but I found some for Sea Witch so that will have to do (same boards).

Based on the schematic I see that the 12V feed from pin #8 on the rectifier board should correspond with pin #12 on the J3 connector on the SDB. I checked the back of this pin on the SDB - 7.3V ??

Then I realized what I did wrong... when I was hastily adding the new J3 connector for the rectifier board there were 2 identical orange wires. I remember thinking "these must both be the same or they would have used distinct colors, so order probably isn't important"...

I had switched the 12V and 7.3V pins on the J3 plug to the rectifier board. If I hadn't been anticipating instant success and had taken my time I would have checked the schematics to make sure I had the order okay.

So I fix the pin order, and fire it up again!

...and that's when my dream of a fully working Star Gazer quite literally went up in smoke, as in, smoke wafting out of the top of the backbox. R50 on the SDB has burned up.

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On another front I hadn't plugged J1 into the rectifier board yet. From what I understand, J1 runs power from the rectifier directly to the playfield for GI lighting and the solenoids. With the SDB down for the count I figured why not see if at least the GI was working.

Turning the game on with just the J1 and J2 plugs on the rectifier board (J3 now unplugged so as to not start any more fires) results in an immediate failure of the F4 fuse on the rectifier board.

Looking at the schematics again I can see that the F4 fuse is on the 43VDC line which powers the solenoids. So the problem appears to be a short of some kind on the solenoid circuit.

When I remove pin #6 from the J1 plug (which is the 43VDC solenoid circuit) I can now see that most of the playfield GI is working, at least.

So, here is the audience participation part of this thread, any suggestions on how to troubleshoot the solenoid circuit short?

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Okay, so the SDB is going to need some work. Fortunately(?), I have a Bally Flash Gordon restoration project that I traded for this fall that isn't playable yet, and it has what are supposed to be working boards in it. You seeing a pattern here...

So, pop in the SDB from Flash Gordon, fire it up, no smoke!
...and the test points all read as expected, got 5V where I need it. The only slight outlier is TP5 = 14.82VDC (should be 11.9 +/- 1.4VDC), so that is just slightly high for some reason.

Next step, plug in the MPU. Fire it up, MPU LED lights continously, but no flashes, so no game boot.
Test points on the MPU all read fine, however. With a little help from vid1900 on his Bally/Stern Driver Board Repair thread, I identify that the MPU board has some damage due to battery leakage that I didn't detect previously (apparently I suck at this).

The damage isn't that bad, totally repairable. The worst part is the 5101 socket and C13 below it.

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I saw that thread, will try that technique. I'm guessing I'll want to remove the green solder mask on the bottom as well, any advice on the best way to do that without damaging the trace underneath?

Thanks.

My Flash Gordon has an AllTek MPU board in it, so I swapped it in to Star Gazer, configured the game select dips, and fired it up...
...and instantly the knocker coil locked on. Powered off before anything else burned up that I could tell.

Unplugged the knocker, turned the machine on again. It boots! Got all the flashes from the AllTek and the game seemsl like it is running. Haven't had a chance to try to use the game's tests, etc. yet. What I can see is that the bottom 2/3 of GI on the backboard works, the top sections are not lit. More concerning there are no controlled lamps working at all on the playfield except the Shoot Again insert between the flippers.

Picture was taken with the AllTek MPU in test-mode. I've got 3 lights on the backboard pulsing, and just the Shoot Again lamp on the playfield...

Any suggestions on where to start?

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Thanks, my digikey.ca order just arrived with a bunch of replacement components for the boards and I'm looking forward to fixing up the boards. Btw, Digikey is amazing, shipped my complicated order in under an hour and I received it less than 24 hours later, $8 for overnight shipping or free shipping with > $200 order.

So... in other news... I'm an idiot!

After looking again at the schematics for J1 it became clear I had the dang connector plugged in backwards.

The really good news is now that it's connected the right way, I have working feature lamps, switches, and solenoids on the playfield!

Remaining issues:
1. The knocker still fires and holds on power up if it's connected. Blown transistor?
2. Left flipper seems okay, but pressing the right flipper button instantly shuts the game down, with no flipper movement. After rebooting I only get 6 dings from the AllTek and nothing but GI. I assume the fuse is toast, haven't had a chance to look. Bought a circuit breaker from Digikey and will craft a fuse mount for it before investigating further.

Hi, can you clarify what you mean by "redone"? I assume you mean re-pinned?

Merry xmas, btw!

Had some time today to look at it again. I finished my fuse-mounted circuit-breaker.
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Turns out the left flipper is resetting the game *after* it flips, and the right flipper is blowing the fuse immediately when the button is pressed, without ever moving the flipper.

I tested the diodes and the left flipper eos diode was bad so I replaced it. The left coil reads 0.8ohms on one lug/coil, and 24.2ohms on the other. That can't be good, right?

Which reminds me, somehow this SG has Williams flipper mechs, including double-wound coils. I assume somewhere along the line a previous owner followed Vid1900's advice and replaced the original Stern mechs with newer bally/williams ones. I'm not thrilled by this as I think I would have preferred to experience the original gameplay and flipper feel. Oh well, it is what it is, I can always swap them out for originals when I swap over to a new playfield.

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The right flipper tests fine, 0.8ohms on each coil.

So can the left coil be salvaged?

Would a blown transistor cause the right flipper to blow fuse without moving the flipper first with the coil testing okay? If not, and ideas on that? I didn't check the right flipper button switch yet, could a missing or failed diode on it cause the blown fuse?

Tomorrow I will pull out the SDB and test the transistors.

I found this excellent reference page for determining coil resistance:
https://www.flippers.com/coil-resistance.html

Using this page it seems that the left coil is actually reading correctly, and my right coil must be shorted, which jives better with the right coil frying the resistor when activated.

Okay, further inspection of the flipper coil shows that neither appears to be wired correctly.

I've redone them to match this diagram from Vids flipper rebuild guide thread.
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Now I have 43v at each coil lug and the F4 fuse blows as soon as the flipper button is pressed.

On a brighter note, I've updated the SDB with new capacitors, and removed a failed transistor for the knocker coil. I also implemented the best practice improvements noted in the pinwiki for this board.

I also received my new molex crimper today and used it to separate out of the ground wires that had been doubled up on J3 on the rectifier board, and replace a couple of other pins that were not 100%. I had originally doubled up the ground wires as I didn't have enough .156" pins for all of them on hand - a temporary solution to try to get the game playing while I waited for parts to arrive.

Okay, with a little help from others I've finally gotten the flippers to work!
See https://pinside.com/pinball/forum/topic/vids-guide-to-upgradingrebuilding-flippers/page/33#post-3512076 for details.

Turns out a previous owner had replaced the original Stern flipper assemblies with Williams ones, and in the process had installed coils that are rated for 28v. In SG, running 43v for solenoids they are too powerful, and get hot enough after a few games to burn out the F4 5A fuse.

This also probably explains why my game only had two of the three original pop bumper caps as it would not take long for the installed coils to destroy the center bumper post and drop targets.

I'll be ordering new classic Stern flipper assemblies shortly to return this game to its original play/feel.

In the meantime I've got playfield lights out, poor quality touchups to remove, a top string of lights in the backglass not working, and of course, the original Stern boards to refresh...

Little update, I've ordered the new Classic Stern flipper mechs + the J-25-475/34-4500 coils from Pinball Life (http://www.pinballlife.com/index.php?p=product&id=2411).

I'm also looking for a single original pop bumper cap for my game, which only came with two. See https://pinside.com/pinball/market/classifieds/ad/43564.

I picked up one of the "reproduction" ones from Marco awhile back but it looks totally different from the 2 originals, not only missing the engraved outer ring of blue lines, but the overall colour is more semi-transparent yellowish white than the white of the originals.

The only other viable alternative might be to get 3 blank white ones and use decals to approximate the original's appearance, as some others have done. Since my long term plan is to install a reproduction playfield and backglass I'd really prefer to have a complete original set for the game if possible. PM me if you have one you'd be willing to contribute to the cause (I'm happy to pay for it, of course).

While I wait for the new flipper mechs to arrive I turned my attention back to the playfield.

Today I removed most of the playfield touchups. There were a lot of "lumps" of paint on the playfield where a previous owner had tried to cover the spots where the playfield was worn, or even where the planking was showing lines through the paint. I much prefer the natural patina of a well played game vs a quicky touchup job, so off it came.

To remove the paint I used a microfiber cloth with a little window cleaner sprayed on it. This took most of the touchup paint right off, though a little elbow grease was required to get the thicker spots. I did leave a smattering of the blue touchup paint closer to the top of the playfield as removing it it would have exposed a lot of bare wood there and is far enough away from the player to not stand out too much.

Once I finished that, and general pf cleaning, I waxed the playfield using the "hot wax" method that I once saw Tim Arnold use on one of his videos. I started with a small hair dryer but it wasn't melting the wax, so I switched to my heat gun on low setting. It was kind of fun watching the wax melt right before my eyes. It probably goes without saying that extreme car should be taken when using a heat gun on a pinball machine. I removed all the plastics before I started but was worried it might damage the inserts. Trick is to keep moving slowly and not spent too long in one place.
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I did cause some bubbling in one spot behind the right flipper. Given the overall poor condition of this playfield it's not all that noticeable.
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The hot wax method didn't really leave a brilliant shine on the playfield so I went ahead and buffed it by hand with a clean microfiber cloth. Given the high risk and less than stellar results I wouldn't bother with it again, but it was interesting to try it.

Playfield is probably as good as it's going to get until a repro is in hand. Looks much better without the touchups and waxed!

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Looking at this blacked out section of GI in the backbox...
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...I was expecting a wiring issue with so many contiguous lights out. But nope, all just burned out, apparently. It was a bit strange because swapping the bulbs out for new ones made them all shine nice and bright, but some of the bulbs I was pulling out looked new as well, no obvious signs of a broken filiment or burning, but they were no good.

Kind of neat to be using up a few of my stockpile of incandenscent bulbs for this, I especially like the 455's used behind the "Star Gazer" letters. Old school!

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Exciting news - my new flipper assemblies arrived!

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Shiny and clean, but out of the box they aren't really setup for use, more just quickly put together to keep the parts together. I had to reverse the coil (and the sleeve), tighten everything down, and adjust the switch on one of them so it wouldn't bind against the coil plate.

While I had them on the bench I ran wires to eos switches...
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...and adjusted the eos gap to precisely 1/8", as per vid1900 's advice on the flipper rebuild thread.
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When I went to mount them to the playfield, I wasn't too surprised to discover that all the original flipper plate screw holes were completely blown out. A couple of them had even been drilled through the playfield where it wouldn't show from above (they ended under the apron). Possibly another reason a previous owner had tried to install the Williams mechs as they would have used fresh screw holes.

The easy fix for this is to dip a thick toothpick or bbq skewer in some good wood glue, insert it into the screw hole, and break it off. On a few holes I had to insert two of them to fill the hole enough for the original screws to tighten nicely.
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After completing soldering the flipper wires to the coil lugs the game is finally ready to play!!
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Having now played a few games I'm finding the flippers to be plenty strong enough. I'm even getting a fair number of balls hitting the glass after hitting a post, etc. I figure I can either increase the eos switch gap to try to weaken the flippers a bit, or possibly increase the playfield slope angle.

I looked in the manual but couldn't find any reference to the intended playfield angle. The game is currently at about 5.6 degrees.

Can someone post what the spec. is for playfield angle on a classic Stern?

Yes, it's great to finally be able to play it!

It plays like I remember the one in Vancouver playing, very different from most games, it's sort of "zen" with it's new age sound effects and somewhat floaty ball movement (lots of side-to-side).

I can totally see myself playing this after a long day when I might not be up for a more intense game like Metallica or STTNG.

Before I can adjust the playfield angle I need to do something about the rusty levellers on the back, and the complete lack of levellers on the front!

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CLR cleaned the rear one up a bit but it still wouldn't budge, so out comes the rotary tool. Nothing nicer than grinding metal in the middle of your rec. room's carpeted floor (don't tell the Mrs.)...
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Another funny quirk is that the legs are labelled on the inside "front-left", "rear-right", etc. for some reason, but the ones labelled "front..." are the ones with the levellers on them, and the ones labelled "rear-..." have no levellers, so I switched them around when I put the legs on the game so it would at least be playable. The legs are all the same length anyway.

With shiny new levellers in place the game is ready for playfield height adjustments and levelling.

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Well, the coils were the ones specified in the manual, so I guess it's stock. They feel fine, just the ball really sails around on the freshly waxed playfield.

I couldn't find any mention of specific playfield angle settings for a classic Stern, or even a Bally of the same era, so I played around with a couple of settings and found that at 5.5 degrees the ball is pretty floaty, a bit similar in feel to an EM. When I go all the way up to 6.0 degrees, the game is much faster. I get more action at the pop bumpers as the ball has a greater tendency to "fall" back onto the bumper after hitting one of the zodiac targets, so that seems like a plus. But all in all it made the game very fast and I felt that it kind of lost a bit of its charm when the ball is moving a bit slower. I'm playing now at 5.75 degrees and it seems "about right" I think.

I would love to hear what angles other SG owners are using and their comments on how they like the game to play, etc.

While I had my new electronic angle meter thingy out I checked my Black Knight. It has been sitting at 9.1 degrees for the last 15 years or so (basically as high as the back levellers can go)! No wonder it plays so mean...

So I dropped it down to 8.5 degrees and it's actually a lot more fun now. Just not something that ever occurred to me to revisit I guess.

Really? How can you tell?

I'm pretty sure they are Stern legs.

They measure 28 1/2", and the shape looks the same as other classic Sterns that I can find pictures of. They have been painted at some point.

Star Gazer LegMeteor Legs

Another job done, added the missing lamp socket for the front pop-bumper cap. Pinball Life didn't have the bayonent style (44) socket for pop bumpers so I had to use a 555 style.
BeforeAfter

It's much nicer having the light there in the middle of the playfield, though it's a bit brighter than the other 2 original style pop bumper caps.

That reminds me, the backglass on this game is very bright and reflects like crazy off the playfield glass. I replaced all the #44 bulbs with #47's in the backglass and that helped a bit, also reduces the light spotting a bit in the BG, looks better overall. I also replaced the scratched up glass with a fresh sheet.

The #44s I pulled are really nice old-school domestic ones that I'll be re-using for the GI in my IJ restore. I've yet to see an IJ with LEDs in the GI that doesn't look flat/"dead" compared to the warm glow that full-spectrum incandesant bulbs provide.

At this point, with the game up and playing, you might be thinking "I guess that Star Gazer has risen now...", but, alas, there is always more to do.

Here is the list of issues that I'd like to tackle in the short-term before moving on / back to my Flash Gordon playfield re-populate project:

1. Loose posts. I have a couple of posts that are coming loose with play. I noticed that my game is missing the plastic post on the left side of the right-hand spinner, with just a small metal post there instead. I'm okay with this for now, can look at replacing the plastic post when I do a playfield swap. However, it has also come loose once causing a lot of airballs as it takes a lot of direct hits (hey, I don't *always* hit the spinner when I want to...). Also, the plastic post that acts as the anchor for the right side of the spinner is also coming loose and won't hold anymore. I think I'm going to have to fill the hole with something strong and re-drill/anchor them to solve this?
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2. Loose insert(s). The left Special insert is completely loose and blocks the ball occaisionally. I'll need to re-level and glue any loose inserts.

3. Flaky insert lamps. I have a number of controlled lamps that seem to work or not depending on the moment. For most of these I'm quite sure it's just socket issues, but the two special inserts have never worked and don't show any power on the multimeter, so might be more going on there.

4. Backglass Score Windows. It looks like a previous owner used the "Saran-wrap" technique to save the flaking backglass when they triple-thicked it. The good news is they ended up with a pretty decent backglass if you don't look too close. The bad news is they didn't cover the score windows, so they are all rippled now. I'm thinking I should be able to clean these up with some delicate razor-blade work.

5. Player-3 score display missing top row. For some reason the player-3 score display never lights the top row segments. Other wise it's nice and bright so guessing maybe a bad solder joint or broken wire in the display unit?
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6. Stolen boards. Right now the game is running using an AllTek MPU board and Bally Solenoid Driver Board I stole from my Flash Gordon project machine. I need to diagnose and rebuild the original two Stern boards so I can give the others back to Flash Gordon. I really want to use the original Stern MPU board because eventually I want to install the custom modified V-9 ROMs for it that improve the game, and this cannot be done using an AllTek board.

So as you can see, there's a fair amount here still. The first 2 are top priority to keep the game playing, them I'll probably move on to the board work. As always, any advice is appreciated!

Thanks for the tips.

When I go to order parts to replace R50 that burned up on the Solenoid Driver Board, besides the large capacitors, are there any other components I should replace (or test)?

Time for some board work.

I cleaned up the MPU board, removing the solder mask along the bottom edge with a copper brush on a dremel. When my copper brush wore out I switched to a grinding stone which also worked but ended scratching the board in a few spots (mild cosmetic damage).

Then I cut out the bottom 1/2 of the U8 socket, and removed C8 and C23. These were the only components that seemed to have any contact with the alkaline.

I used the toilet bowl cleaner method to neutralize the alkalinity on the board. This seemed to go well though I only noticed a small amount of bubbling. I had very little crystalization on the board so perhaps there wasn't that much to neutralize.

I replaced the bottom 1/2 of the U8 socket, and put in new capacitors for C23 and C8. The board trace for U8, pin 8 (ground) was shot so I used a small jumper wire there to work around the missing trace.

Then I added a new large capacitor to replace the orignal battery so the volatile memory will be preserved so long a the game gets turned on relatively often, which is fine for my needs/usage.

Finally, I covered the exposed traces with solder to avoid future corrosion.

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Next up I put together my MPU test harness on the workbench as instructed in PinWiki, using an old ATX power supply from a really old PC I've had sitting in the storage room for like a decade. I must have been saving it for just this occasion!

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The MPU comes up with a locked on red LED.

Shorting U9, pin 40 and 39 doesn't do anything (possible it could jump start the boot sequence).

So I worked though the various tests as described in PinWiki using my multi-meter and logic probe...

Removed all ICs except U6, U9, U11, and the roms.

All of the following power readings are correct:
"U6, U2 (ROM): +5 = pin 24, GND = pin 12
U9 (CPU): +5 = pin 8, GND = pin 1 or 21
U10,U11 (PIA): +5 = pin 20, GND = pin 1
U8 (5101): +5 = pin 22, GND = pin 8
U7 (6810): +5 = pin 24, GND = pin 1"

U9:
- P3, P36, P37=Pulsing (good clock)
- P2, P40 = 5vdc (good)
- P5 = No pulse, Low. (BAD)

According to PinWiki: "Check U9 Pin 5. This is the VMA line. It is a pulsing signal and reads about 2.8v with a DMM. If incorrect first try a new U9. Next check U14D, U15C, U19B. U15 is the most likely IC to have failed."

So I've got no pulse using the logic probe on U9, Pin 5.

Should I be trying to find a new 6800 chip at this point, or are there other tests/components that could cause this that I should look at first?

Don't worry I've read your thread a couple times!

Already grabbed the pop bumper scan and spinner scans I'll need in the future as well.

Question: which bumper caps did you use to apply the decals to? Did you paint them white first?

Thanks! I haven't done a lot of board troubleshooting (been lucky that way) but am trying to learn as much as I can now.

Looking at the schematics I see that Q13 drives the top-line segment of the display. What I don't understand is why only the Player 3 display is affected? If Q13 was failing wouldn't it affect all the displays?

You mean a pic of the bottom edge of the legs? What will that show?