Quoted from JohnBillerman:

Thanks inkochnito,
I verified continuity between SDB J4-8 and CPU J4-7 - also past the headers into the board.
The relay pulls in during solenoid test mode and when grounding Q15 (in attract mode only.)
Any next steps?
I believe the traces in the damaged area all buzzed out earlier, but maybe I'd better take another look down there.

Quoted from Spitfiren8:

Can anyone let me know if its safe to slave in a medusa mpu into my flash gordon for troubleshooting? Im trying to nail down a reset issue im having.

Quoted from desertT1:

I replaced this cap today and the game played at least 10 times and no resets. Thanks for the suggestion, seemed to be exactly what was needed.

Quoted from statictrance:

So I'm looking at the manual and can't find a switch matrix for the life of me. I know this era is a 5x8 array and am trying to pinpoint some odd behavior.
Anyone have any idea where to find the switch matrix for a strikes and spares online? Or is it as easy as writing down the switches in order (if so, is it 1, 2, 3 down the first column, or across the row?)
Also - any tips if you get a credit by wiggling a controlled lamp? (Not kidding... Figured I'd start with tracing the wire but had to ask)

Quoted from Chalkey:

Why did this dude add resistors to the digit drivers?
[quoted image]

Quoted from MrSanRamon:

Does anyone know where i can get a Bally Night Rider (SS) lamp matrix?
Robert

Quoted from jsa:

I will check them, there are two of these (I believe a 9 and possibly a 14 or 20). I don’t believe the colors/positions are documented anywhere, so my best course is to check that colors continue through the connectors. If anyone can find it documented let me know.

Quoted from Aladdin:

Tech Question:
Bally Evel Knievel
Feature Lights shut off once the game warms up
I then shut the game off and turned back on, and this time once the game warmed up, the Feature Lights froze?
Is this due to a Bridge Rectifier going bad?
I'm thinking I need to just rebuild the Power Supply Board and see where that takes me?

Quoted from Robotworkshop:

Question about the Bally and Stern Solienoid driver boards. It it my understanding that the regular Bally AS-2518 and Stern SDU-100 boards are interchangeable. Upon looking over a couple versions of the Bally board I noticed something odd on J3. On one of the Bally boards pins 18-24 are all tied together on the back of the board. On a different Bally board and the Stern board pins 23 and 24 are separate from pins 18-22.
I'd like to verify that there isn't a solder bridge on that first Bally board or if it is ok if the other boards should be bridged the same to tie grounds together at the board.

Quoted from Robotworkshop:

Hello Peter,
I've added the extra jumpers on the board but the Wiki never mentioned tying the grounds on pins 23 and 24 to the others on 18-22 or that some versions already had those tied together. I guess if they should be then that would be good to update the Wiki. I didn't know there was a difference until I had a couple different versions of the board and thought one may have had a solder bridge.

Quoted from Quench:

Another difference between the two solenoid driver boards is that Bally fitted a 2.2 ohm resistor at R50, while Stern fitted a 4.7 ohm resistor which results in their 5V supply being a fraction higher (around 5.2 volts compared to Ballys 5.1 volts.).

Quoted from Robotworkshop:

This Bally AS-2518-22 has the ground for pins 18 through 24 all tied together. This board has a fuse for the display power.
Since this looks like a newer board it seems that maybe the earlier boards could be updated the same way. Is anyone already combining the grounds like this on the earlier boards?
[quoted image][quoted image]

Quoted from Heaterguy:

Thanks, I think LOL....Wierd stuff is happening, on game start the pop bumpers pop instead of chimes.
I soldered the jumper because I was not getting voltage and now solenoids fire but the pop bumpers are firing instead of the Chimes, the out hole and saucer do not fire (including when in self test) During self test when the Chimes should fire, the pop bumpers fire and one of the left lower slingshots fire. Same thing during game play. I'm certain the J plugs are connected correctly to the solenoid driver board I even verified the wire colors in the connectors and re pinned them. I have the correct game configured for the alltek mpu. I am going to do a memory clear and reset for strikes and Spares and see what that does.[quoted image]

Quoted from Heaterguy:

Wow Thank you thank you thank you! Upon close inspection there are 3 other ones even worse. (Loose)
I did not even think to reflow the pins as I have not had to do that except for one other machine. Will definitely do that when I replace C 23. One more question I have is the smaller red Molex connector pins....are they .100 or .093 Size? I have .156 trifuricons and re pinned those already but need about 200 of the smaller ones and don’t have any, as I have not had to do these type before. Do they remove the same way as the .156 pins do?

Quoted from desertT1:

The flippers died on my Stars on location. I’m getting power to the coils, but not to the cabinet buttons. When a game starts I don’t see/hear the relay power up. Q15 measures the same as other transistors, so I think that’s good. Check solder and reflowed headers anyway. What are the odds the relay actually went bad? Those tend to be pretty robust in my experience.

Quoted from Robotworkshop:

What is everyone setting the voltage to for the displays? Manual shows it should be 190v +-5v. I know on some of the older Williams you can drop the voltage a little to extend the life of the displays. Just wanted to see if others are doing that on the Bally/Stern machines too and if so what are you setting the voltage to?

Quoted from desertT1:

Stern Stars is struggling to kick out a ball. The drops were struggling to reset as well. It’s as if the voltage dropped, but the flippers seem to be fine. Suggestions?

Quoted from Mathazar:

I then took a closer look at the J3 connector (specifically the jumper wire connecting pins 13 and 25). No continuity. I pulled the jumper wire out, and sure enough one of the pins that I had re-pinned months earlier was mangled. I re-pinned the jumper wire, put it back in, removed the TP1 to TP3 alligator clips, and everything works again with the Bally SDB.
The Alltek board apparently does not need that jumper wire present in the J3 connector. I screwed up the crimp months ago and never knew it because the Alltek board just worked. When the Bally SDB didn't work, I never suspected there to be a wire issue given that the Alltek worked fine!
[quoted image]

Quoted from Chalkey:

What's the easiest way to move a Bally LE cab? Removing the head and wrapping / strapping it to the body the same as a normal cab? The bottom section with the score displays stays put right?

Quoted from Quench:

The wire gauge is a similar thickness to the other factory jumper links on the board. Holes are 0.8mm drill diameter.
You can use component lead clippings similar gauge to the jumper links already on the board to do the job.
I do the same with the C26 and C23 capacitor ground mods although I use thicker gauge component lead clippings for the C23 mod because of higher C23 surge currents on power-up.

Quoted from RobDutch:

Can't start a game on my Lost World.
It does not boot for some reason (not a single flash) and the green led stays on.
All testpoints are getting their voltages and all ic sockets have been replaced and all connectors are cleaned. (It did not fix it)
Also the displays and insert lights stay off.
It's like the machine doesn't get told what to do; broken rom?
Anyone got a clue? Thanks in advance
[quoted image][quoted image]

Quoted from statictrance:

Alright, have a controlled lamp driving me batty... I've done the following - any ideas?
1 - replaced socket. Can confirm clipping tab to a neighboring tab works.
2 - repinned connector. Twice.
3 - confirmed connection between socket and wire. Ran a brand new wire just to be safe
4 - replaced lamp board from another 100% working Bally game. Still that same one lamp out in game. (Conversely, other game is working 100% with the other board).
Seems it has to be above that - but given how it all works I can't believe the MPU wouldn't only misfire one single lamp. Any ideas of something I missed before I keep swapping and repinning?

Quoted from statictrance:

Son of a bitch .. it had perfect continuity and everything, but I reflowed and there it is. I was leery of it being a reflow/transistor issue, that's why I just swapped boards. Very strange both worked just fine without any adjustment or modification in Mystic
Thank you Inkochnito... That's what I get for being in a rush

Quoted from JethroP:

Can't understand how a bushing going out would cause a high pitch sound. It's not a squeak I hear...it's a high frequency electronic sounding pitch.

Quoted from djblouw:

Thanks for the input.
Will hooking the lamp direct to ground cause any issues (if I wanted a lamp to always be on)? I know I could hook it up to GI, but that a different discussion.

Quoted from guitarded:

Thanks Inko, that's super handy to have!
So it looks like I need replcements for 2N5060 in each of those positions. Anything else I should change along with them?

Quoted from Robotworkshop:

Is that test ROM available?

Quoted from matiou:

Question about the rectifier board...... When the machine is off, playfield and backbox harnesses disconnected from the rectifier board, should I get continuity between the GND test point of the rectifier board and the metal plate underneath ? Because I don't......

Quoted from Quench:

Find return lines I3 to I7 under the playfield, what happens when you body ground them and observe the fast react solenoids on those switch return lines? I think you'll find they do the same thing, i.e. it's not just I5.

Quoted from vec-tor:

Bally playfield switch wiring Note:
Bally switched wire color sequences on ST1 and ST2.
From MPU A4J2.
1) Old Bally Switch wire color code:
ST0 [ 51 ]
ST1 [ 93 ]
ST2 [ 52 ]
ST3 [ 53 ]
ST4 [ 31 ]
up to Bally Hotdoggin / Viking.
--------------------------------
Starting with Skateball
2) New Bally Switch wire color code:
ST0 [ 51 ]
ST1 [ 70 ]
ST2 [ 93 ]
ST3 [ 53 ]
ST4 [ 31 ]
--
Also "L" target bracket changed from just two holes to
one of the holes being more oblong adjustable.

Quoted from Nokoro:

Every single bulb in my game appears to be out.

Quoted from Nokoro:

Interesting. Thanks for the tip.
R2 looks intact on my board and measures 25 ohms as it should.
As I mentioned, connector J1 was misconnected and off by one pin. I wonder whether that could have caused this.

Quoted from RoyGBev:

Yeah didn't notice about the knocker. Couldn't the head also be 6M$M, Voltan(!), Kiss, Harlem or Dolly?
I tried to match the text on the adjustment cards stapled in the backbox with pics from ipdb. It does look like the Eight Ball cards but I'm not sure.

Quoted from desertT1:

Player 2, 4, and the ball/credit display were connected. When removed so no displays were connected there are still crackly sparks.[quoted image][quoted image]

Quoted from hisokajp:

I assume he meant that one:
https://www.pinwiki.com/wiki/index.php?title=Bally/Stern#Solenoid_Driver_Upgrades

Quoted from Nokoro:

I have an old MPU and SDB from a game I acquired. Both boards were swapped out by the prior owner. I'm not sure if either board works. There appears to have been a thermal event above the area where the SDB sits in the backbox. As for the MPU, I'm not an expert, but it appears as if there is some battery leakage. The board smells a bit acidic and is a bit sticky with some areas of corrosion showing.
My question is whether there are parts worth salvaging on either of these. I don't have the skills to fully diagnose and repair, especially with acid damage. Are the socketed chips at least worth removing and keeping? Anything else? Or, would the boards be worth anything in the condition that they are in?
[quoted image]
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Quoted from Phesson:

Thank you Arari_Daze

Quoted from barakandl:

This is an issue with the cheap squeak sound board. Exacerbated by MPUs with longer reset widths.
When the cheap squeak comes out of reset it programs the 6803 processor mode. The pins that program the 6803 mode also happen to be solenoid signals and forces the bit pattern for the outhole. The PIA ports are in Z state during reset making it easy for the cheap squeak to drive those signals, even through the series resistors to the solenoid decoder.
There is potential coil melting problem here. If the MPU and Cheap Squeak are below the 5v power monitor level and stuck in reset, the mode programming diodes on the cheap squeak can lock on a coil. If the cheap squeak and mpu had a reset buttons, if you held them both down, the outhole would lock on until the fuse blows or worse.
I fixed this on the replacement cheap squeak I make. I put in series resistors and a buffer chip between the solenoid signals and the 6803 processor. That way the mode programming will not be able to force the solenoid pattern for the outhole while in reset. All other bally sound boards have a buffer chip on the solenoid input signals. I think the "cheap" part left out that circuit and they decided to just live with the potential coil pulse at power on.
[quoted image]

Quoted from Phesson:

I have a Mata Hari that has all modern boards. It has a problem that I noticed recently. During a 4 player game it will reset. It will play a 1,2 or 3 player game without incident but each time a 4 player game is played, it will reboot.
It is my understanding that most reset issues come from the 5 volt to the mpu dipping. I’m not sure why this would be isolated to a 4 player game.
Any leads on where I would start troubleshooting this issue?

Quoted from jibmums:

I just replaced the LM3900 amplifier in the second Space Invaders sound board, and I have volume again, so that fixes that problem. Still getting the same hum as the first board though, so I also recapped the second, and the damn hum is still there. I get the same hum whether the boards are screwed in tight or floating, which I see was a solution for some owners. Not sure what else I could try.

Quoted from jibmums:

I assume that grounding the - of C13 to the backbox ground braid with an alligator clipped wire that I had handy would do the same thing, so I tried that. Not only didn't it lower or eliminate the hum during a game, but it introduced a new hum, fairly low but still there, during attract mode.

Quoted from jibmums:

Wouldn't I get a hum as soon as the game is switched on then? Hum only begins when I start a game. You can hear it over the "dum-dum-dum-dum" background noise, but when a sound effect plays it momentarily stops, then begins again right after the sound effect stops.

Quoted from jibmums:

Nope, just new caps on both, and new LM3900 amp on one. Both sound boards should be exactly the same now, so I'm guessing the problem has nothing to do with either.

Quoted from Grefla:

or perhaps I could use this
https://www.ezsbc.com/product/psu5-nonoise/
Does anyone have any opinions on this product?

Quoted from gdonovan:

Has Bally Stamped ESBM 8xxx serial number on head in correct location, size and font.

Quoted from kmart00:

The Tech Charts at pinballrebel.com are incorrect for early Bally SS (-17 MPU) machines. For these chime games, they list boards more commonly found on games with electronic sound (-35 MPU).
My Eight Ball still has its AS-2815-14 Lamp Driver and AS-2815-16 Solenoid Driver boards. They work just fine.
[quoted image]

Quoted from Shapeshifter:

I was able to check fuses, tilt switch, and coin door.
No flashes, just the GI lights come on.
There is a very loud buzzing when the connector/wires are moved - bottom left in photo. J2.
Maybe just a different fault, not sure.
It will be a while before we go through the Pinwiki voltages though.
Thanks for the suggestions.
[quoted image]

Quoted from mad_carl:

working my way through some issues on a Rolling Stones and I found a clipped yellow wire on the memory coils for the 4 bank drop targets. I didn't even realize this game had them until I found the wire.
Anyway I re-soldered it, and now the coil locks on at power up. Obviously why it was clipped. It's pretty toasty. And it's just that 1 coil of the 4 of them where the power comes in.
Maybe I'm blind but I can't find the memory coils in the schematics online. I check all the transistors on the SDB, and they all read similar so I couldn't pin point it. Am I missing something?