IKIK! I’ve been fighting a switch problem on my “new”
STTNG for the last couple weeks. Left outlane is triggering Trough 2. Nothing else seems wrong. Thought it was a bad diode at first but can’t construct a rectangle that makes any sense.
I swapped in a different trough receiver board and STTNG is now working fine. The diodes on the original all test fine so I’m now thinking the comparator for Trough 2 is bad.
Receivers are all working fine, inspected and reflowed solder. In switch test Trough 2 (and only T2) fires with no ball present when another switch in that row is pressed. But fixed with alternate receiver board. So seems like it has to be on the receiver board.
Either there's a problem with the wiring harness of there's an issue with the 16-opto board.
The game keeps losing all switch inputs from that board but it's happening randomly. I'm pretty sure there was a bad connection somewhere in the harness. Hasn't glitched in about an hour!
Did you know that on most WPC games you can press Start on some switch, individual lamp or solenoid tests to get more info about which fuse, drive transistor and other info to check? (Depending on however much the individual dev for that game cared to populate the table)
Given that looks like a Star Trek TNG pinball, the ball opto troughs on those are notorious for cracked solder joints on the LEDs and power resistors from vibrations.
There are several retrofit kits you can buy with replacement PCBs that are mounted on rubber shock mounts, eliminating the problem.
I've got (or had) a problem which was taking out at least a whole row of switch inputs from the opto board. I think it was in the harness coming from the 16-opto board, and there's evidence of a repair, but if it comes back I'll see if I can isolate what's knocking that row out.
It's not unheard of for the pin headers on that 16-opto PCB to crack. The tunnel ball divider coils really slam the playfield around, and shake things.
Pull the PCB and reflow all ita solder joints behind the pins headers.
Games of this era were also known for bad LM339 ICs. Labeled BA10339.
I've already reflowed most everything on that board ;)
I thought it might be possible there's a bad IC, but I'll have to look at the schematics to see if the things that fail together can be blamed to a common chip.
Growing up with an arcade route run by my father, I remember digging through all these menus so many times. That switch debug table was a bit impenetrable as a kid, but those menu buttons in the coin door all make great noises (especially the one that goes *dig-id-id-id*).
This is where you go to test the switch inputs in Bally/Williams pinball machines from the '90s. I'm diagnosing an intermittent problem which I've narrowed down to a particular set of switches which share wiring.
This is my absolute favorite. Besides the fact that it’s TNG, it always felt like it wasn’t “cheating” you out of your quarters. I ALWAYS play this one if I see it in the wild.
When I was QA in a large manufacturing facility I would often have problems that would just go away, and I hated that.
I want to be able to turn the problem on and off so I know I really fixed it.
(There were a lot of inputs and cascading / multiplying effects, basically)
The problem fixed by an unknown solution: The practical side is happy to be past with it. The pedantic side aches to know WHAT FIXED IT?! WHAT IF IT HAPPENS AGAIN!? WHY CAN’T I FIGURE THIS OUT?! 😫
I get the uncertainty over a common intermittent wiring problem. I've had at least 2 vehicles where a wire in the middle of a bundle would intermittently short to ground, or be intermittently open/closed. Blew a bunch of fuses for the AC in one vehicle, in another the heater/a-c fan would drop out.
Sometimes you just throw everything at a problem and nothing fixes it, then you do something seemingly unrelated and everything is fixed. Arcades of all kinds are so temperamental, I swear they have minds of their own.
That's how this game is behaving. I thought it was down to the CPU board (it would randomly just... start doing stuff, even without a game in-play) but I finally caught a bunch of switch inputs suddenly firing at once.
And given how the game stages balls under the playfield, it finally made sense.
It's losing all the switch inputs from the opto board which is running optical emitters and receivers to determine where balls are. So suddenly it thinks three balls just disappeared and it starts looking for them.
Imposter syndrome is when you're good at something but feel like you're just pretending. If you're using chatgpt for programming, you actually are just an imposter
I do love that you are one of those rare types of people that after posting "If you know, you know" (spelled out even, so we don't have to remember what the abbreviation means!) and puts what it is in the comments for those of us that don't know. You value sharing knowledge rather than not. 💚
Comments
STTNG for the last couple weeks. Left outlane is triggering Trough 2. Nothing else seems wrong. Thought it was a bad diode at first but can’t construct a rectangle that makes any sense.
Using switch *edges*, first unplug both the 16-opto *and* the ball trough and test every switch.
Then repeat with just ball trough. Then add the 16opto PCB.
Those take simple light inputs - there's no pulsing or coding.
You can plug the board in, go into Switch Edges test, and test each opto receiver with a flashlight
Additionally D9 is on the column strobe, but I don't think you have an issue there.
For a home game, a new H-17067 harness in each launcher is basically a permanent fix; you'll never put enough plays on it for it to re-break.
The game keeps losing all switch inputs from that board but it's happening randomly. I'm pretty sure there was a bad connection somewhere in the harness. Hasn't glitched in about an hour!
if it was played by someone who is very bad at tetris
There are several retrofit kits you can buy with replacement PCBs that are mounted on rubber shock mounts, eliminating the problem.
Another common failure on these games is the wire harness to the two ball launcher cannons, that's H-17067.
😎
Pull the PCB and reflow all ita solder joints behind the pins headers.
Games of this era were also known for bad LM339 ICs. Labeled BA10339.
I thought it might be possible there's a bad IC, but I'll have to look at the schematics to see if the things that fail together can be blamed to a common chip.
The good news is I think I fixed it!
The bad news is I have no idea how.
Is this how weird rituals get started????
If I do this, it will work for some reason....
So that's the deep metaphysical answer that stops the bullets, Neo?
Cz I'm pretty sure we should stop the bullets.
Try to stop the bullets.
Obviously.
I want to be able to turn the problem on and off so I know I really fixed it.
(There were a lot of inputs and cascading / multiplying effects, basically)
"So... do we try to recreate the error until we potentially break it even worse, or do we just send it back to the client and *hope* it stays fixed?"
Being your own client removes a lot of the anxiety but very little of the frustration.
Are you sure you're not doing programming? This looks a lot like programming.
but this has been the most troublesome issue I've dealt with
And given how the game stages balls under the playfield, it finally made sense.
At least I'm 90% sure that's what's going on.
I don't know how or why that's enough for me to dive right into these things but once you're a tinkerer you're always a tinkerer.
When a problem goes away on its own, it'll return on its own.
"This doesn't work, and I don't understand why not"
The MOST frustrating thing is:
"This DOES work, and I don't understand how"
https://mez.ink/dewaterbang.vvip