My Who Dunnit project is nearing completion. I printed the first production version of the reel and applied the decal to it. I intended to buy a set of decals, but this one peeled off intact. I had feared I'd never get it to look good, but this filament saved my day, I tip my had to Formfutura for their clear HDglass PETG. #pinball #pinrepair #arcaderepair #3dprinted

I encountered an odd problem with Jaws. I booted the game up to check it before cleaning and I had an operator alert about the shark fin being disabled. The game asked me to run the test to enable it, I ran it back and forth couple of times and could not immediately see any of the position optos do anything funny.

As you can see from the video, the solenoid that kicks the shark fin up is pretty violent, these games suffer from so many solder cracks in connections thanks to the lead free solder used, although I assume the materials have become better from the early lead free solder that developed cracks if you looked at it wrong.

I examined the board with a magnifying glass, it appears to be intact. I'll chalk this one up as a fluke and come back to it if it starts acting up more frequently.

#pinrepair #arcaderepair #electronics #pinball #arcade #retrotech

Mister Bond is no longer dirty, he's actually so shiny you can see the perfect backbox reflection off the playfield! #pinrepair #arcaderepair #pinball #arcade

The lamp tests have become a lot less eventful when the games went natively to LEDs and there's virtually no lamp sockets to mess up things either. #pinball #arcade #arcaderepair #pinrepair

Who Dunnit is having bit of a crap day. Last Wednesday a player reported the rightmost reel in its slot machine behaved oddly. I made a note it didn't seem to find its zero position and it rotated somehow oddly, so I just disabled them as the game doesn't need this mechanism to be played.

Today on investigation I found that the whole reel is somehow wobbly. I pulled the whole mech to investigate and sure enough, the motor is bad and it has probably ran so hot at some point it warped the plastic reel.

The reel itself has pretty simple geometry, I'm contemplating on just modeling it in CAD and printing it out of translucent filament. I already have some improvements in mind on its design. The decal is apparently easily available, as is the motor as it's just pretty standard stepper.

#pinball #pinrepair #arcade #arcaderepair #slotmachine #repair

I've posted some videos of leg bolts with bad back plates. I've often been told in the comments that it's going to be a horrible job to fix it.

I never got that take, the backplate in WPC games for example is just 6 small screws away from being pulled off. In a lot of classic games there's a very thin metal plate back there that can be replaced with an upgraded one easily.

#pinball #pinrepair #arcaderepair #repair

I investigated the Elvira's opto issue further. As I suspected, it has a design flaw, similar to the ramps; the hole for the opto switch's LED to shine through is misaligned.

1st pic: The two holes seen in the ramp that's attached to the playfield back board are for the solenoid that keeps the ball there and its opto switch. They're so close to each other that the opto has to be pushed all the way to the right so it won't touch the solenoid's plunger and thanks to this, it's nearly impossible to have it perfectly centered in the hole.

2nd pic: The opto's hole in the ramp is bit offset from the ball's path, so I did what I did with the right ramp earlier and drilled the whole 1mm larger. Now the opto was relatively easy to align

3rd pic: Now the opto board doesn't touch the plunger, so it probably won't start to move again in the long run. Still, this is a bit iffy design, which appears to be the theme in this gameplay-wise excellent game.

#pinball #pinrepair #arcaderepair #arcade

@boyago "Oh that construction site game? The heads are so adorable!"

The heads:

#pinball #pinrepair #arcaderepair

I got a report that Guardians of the Galaxy wasn't seeing the drop target being dropped. The target mechanism itself worked fine and since it uses an opto fork switch, they're usually pretty long life if they get q-tipped every now and then.

But immediately seeing the the tech alert complaining about other switches that are physically near made me think it's all related.

A lot of pinball machines uses a 8 by 8 matrix for 64 switches, the Stern Spike platform however uses individual switch inputs that get grounded when a switch is activated. While the return wires are individual, the switches around same physical area share one daisy-chained ground wire.

Finding the issue was made so much easier by the fact that it wasn't yet completely severed, so tapping the wire bundle made it see the drop target momentarily. And just as expected, the ground wire was broken from upstream. Portasol saved the day.

#pinball #arcade #arcaderepair #retrotech #retrogaming

My NBA Fast Break's shot clock (the two large 7-segments at the back) was partially dead when I bought the game. I couldn't source the exact same 7-segments used in this game (those are huge, I think 1.8") so I got the closest I could find and built a custom PCB to hold them. I wasn't sure if that'd hold, but it has now been there like a year and it's still working. Plus I like these tad bigger 7-segments compared to the original ones.

#pinball #arcade #arcaderepair #pinrepair

Most controlled lights in a pinball machine are in a matrix, typically in a 8x8 one. There's 8 transistors to feed power to the columns and 8 to connect the rows to ground. Technically it's a lot simpler than to drive each lamp individually and by software magic and incandescent bulbs the player doesn't see the scanning.

As cool as it is, things can go wrong. A failed transistor kills the whole column/row, ditto with a single broken wire. They also have diode in each to prevent the current flowing in wrong places. A shorted or open diode can cause issues.

Here's one quick debug session of Williams WPC platform ('89 - '98) lamp matrix. There's some lamps out and they suspiciously seem to make a pattern. The bulbs themselves are good too.

From the matrix chart we see they're all on row 4, with red-yellow wire. Now all we need to do is to follow the wire and see where it's broken.

This one was easy, but at times the problem spot can be pretty painful to find!

#pinrepair #pinball #arcaderepair #electronics

I let it run in the test for a while and could not repeat the issue. Before it had like maybe 1 in 10 chance to get stuck in up position. Naturally the test alone won't recreate the conditions it receives when played, but I'm hopeful. I'll order the worn out part next time I'm ordering stuff from a store that carries it. Or it'll be one of those things that got hacked and it works another 10 years.

Can't believe RFM turns 27 years this year! I still remember seeing one freshly unboxed in the summer of '99!

#pinball #pinrepair #arcaderepair

I suspected the solenoid, but it was this sliding surface that was deep grooves in it. The mechanism has enough play to cause it to stick because of them. I'll replace it, but as I don't have a spare at hand, I'll dremel down the worst of it and see if it lasts until a spare arrives. #pinball #pinrepair #arcaderepair

There's some mechanisms that use flipper coils in unexpected ways. This is Revenge from Mars' jumping ramp, that stays up extended times, resulting normal single coil overheating.

This thing is starting to stick in up position and I'm investigating why. #pinball #pinrepair #arcaderepair #mechanism

I pulled the receiver side of the optical ball trough and I see someone else has also worked on this, there's some flux around the connector pins. The weird flickering issue with the switches disappeared when I wiggled the connector, so I have a strong suspicion about these insulation displacement connectors, virtually every other connector in the game uses individually crimped ones, including the other SPI bus on the same node board where this one terminates to.

The wiring harness got all new connectors and from a quick test game, the game no longer freaks out randomly during multiballs.

#pinball #pinrepair #arcaderepair

Last time I had to deal with this issue with vice grips, but this time there was not enough screw remains left to get a grip. Alternative approach was to use the Dremel tool to cut a slot at the end of the screw and use a flathead screw driver to get the remains out.

After checking the coil stops (a really weak part in this platform!), I used better quality screws to put this thing back together. I really need to check my other Sterns, I think most have the factory screws replaced with something that isn't made of wet toilet paper, but fishing these screw remains is so annoying I might as well replace the rest too.

#pinball #pinrepair #arcaderepair

I'm scratching my head with the Guardians' ball through board. It's the Node 8a in this picture.

For those new to this design, Stern uses Node boards that each house their own microcontroller and they talk to the backbox computer, called Node 0 while handling a lot of real time stuff autonomically.

These boards also do SPI and they have chains of SPI devices on smaller boards (called a, b, c...) that can do LEDs, drive motors etc. The node boards themselves come in various models, but they can also drive LEDs and almost always carry transistors for solenoid drives too.

Blue lines in the diagram are inter-node board (Proprietary?) communication and dotted purple ones SPI.

The intelligent Node 8 board seems to drive a lot of SPI devices, with the problematic board being just a lone device in that bus. Bad cabling or cracks in pin solder? I may need to pull the board and give it a closer look.

If I see nothing extra, I'll see if the problem goes to another game if I swap boards.

#pinrepair #arcaderepair

Well would you look at that, a new failure mode for me. This Spike 2 game has blinking optos in the ball trough, causing it to be confused mid-game. After observing the ball trough board LEDs, I don't see this blinking effect with bare eye, but it's very visible in the ball trough test. I wonder if I'm looking at a communication issue between the node board and this thing or if something's failing internally on this board. #pinball #pinrepair #arcaderepair

I rebuilt Mando's flippers last spring. Now a player reports the left flipper is dead. I still have in fresh memory the times where the plastic plunger links had the structural integrity of wet toilet paper and was surprised that the actual failure was the tiny spring pin that was so loose it fell out.

I tried reinserting it but it didn't want to stay. I didn't have the pins as spares but had a boxful of the whole plunger+link assemblies, so I just replaced the whole thing. Normally I replace wear parts from both sides, but the wear was so minimal on the right side from 6 months of use that I left it. But do notice how dirty they get in that time! #pinball #pinrepair #arcaderepair

Ah, the fun part in owning pins: finding a loose screw in the cabinet. Always a hoot to find where they came off from. A lot of parts in Sterns don't have Loctite in them, I use the blue version in most places. #pinball #pinrepair #arcaderepair