Re-Capped Mac SE/30 Motherboard

It’s time once again for something decidedly non-pinball – a quick post about replacing the capacitors on my Mac SE/30’s motherboard. Although computers have used surface mount parts for decades now, all of the soldering work I’ve done on pinball machines and various other projects has been through-hole only, so this was a new skill for me to learn – and a new tool needed!

I picked up a hot air re-work station for 38$ on amazon – an essential tool for doing surface mount work. Instead of heating joints directly using an iron, hot air soldering involves shooting hot air to heat the entire area around a component. This means you can solder (or un-solder!) multiple joints simultaneously, making removing ICs with many joints arguably even easier than with through-hole soldering.

So on to the Mac motherboard. The electrolytic capacitors used on the SE/30 are known to fail, and once they do the computer will exhibit various different problems – mine would often give me a zebra (striped) patter on screen when powered up, and when it did boot up  the sound was very very quiet. Both problems are linked to leaking/failed capacitors.

Here’s a photo of the electrolytic caps before the repair – it’s a bit hard to see in the photo, but the goop inside the caps has leaked all over the surrounding areas of the board.

On to the repairs! I started with one of the caps nearest the edge of the board, and used aluminum foil as a poor-man’s heat shield to protect nearby components. Hot air is great at getting multiple joints melted for easy component removal, but this also means you may melt the joints on nearby components you don’t intend to un-solder. It’s not really a big deal in many cases, but you have to be careful not to move those components when the joints are melted. You also want to protect any components that are at risk of melting such as plastic or nylon parts, as during manufacturing it’s quite possible those were put in using wave soldering and are not capable of withstanding the heat used in hot air soldering.

Here’s a photo of the replacement cap installed. It’s a different type – a tantalum capacitor which has no liquid inside and hence will never leak! Note in particular the stripe on the component indicating polarity is reverse from the original electrolytic ones! I have no idea why this is how they’re marked, but it’s definitely something to be careful of as things will definitely not work if you reverse them.

Definitely not the best soldering work in the world, but serviceable 🙂 I then moved on to the rest of the caps, including the two larger through-hole ones. Compare the “before” photo above with the “after” below: 

The completed board! I checked continuity on every joint before attempting to power up the board, and after re-assembling it into the computer, both symptoms mentioned above were cured. 

As pinball boards move more and more to surface mount components, my hope is some of the skills I learned here may apply to pinball one day 🙂

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Game room carpet upgrade

I undertook a new project recently to upgrade my game room to carpet. One of the main reasons, in addition to the great look, was to cut down on the noise – carpet does a much better job of absorbing noise than hardwood.

So, what carpet to get? I didn’t want to use just “plain” carpet – much too boring! I found a manufacturer, Joy Carpets, that specializes in just the right styles for game rooms – their “Neon Lights” line. The next question I had to answer was exactly what to get an how to lay it down on the floor. I wanted the wall-to-wall look, but without nailing it down to the floor which would damage the nice hardwood underneath. The manufacturer put me in touch with a local distributor, French Brothers Flooring America, which was able to custom-order me a rug made with that carpet but sized exactly to my dimensions! I measured up the room, took off an inch (to account for the room likely not being perfectly square, and sent off my order. A couple weeks later it had arrived (along with a grip mat to lay underneath) and I was off to pick it up.

It took me quite a while to get all the games out of the game room, of course, but I then laid it out and it was just what I was hoping for! It looks great and really gives the feeling of wall-to-wall carpet without the permanent installation. Note the ugly un-covered inch by the right wall will be behind the machines and not visible at the end of the day.

Hoping to cut down on the echoing/noise in the game room even further, I took the opportunity of the room being empty to install some foam panels on the wall. They are the cheap 1″ deep ones, certainly not professional grade, but better than nothing and not pricey.

Of course that’s not the end of this project! One of the cool things about the carpet is that the colored dots are UV (black light) reflective. I thought of installing black lights high up in the room, but I really don’t like the idea of staring into UV LEDs/tubes, so I decided instead to mount the lights underneath the games, but pointed down at the carpet. I bought an 8 foot long piece of pine trim at Lowe’s to fabricate light strips – I made five total, one for each game. Each strip has two black light LED strips each plus wiring long enough to reach the back of the machines.

I then fabricated a daisy-chaining wiring harness to connect all five strips to one power supply. Here are all the strips being tested on the wiring harness for the first time:

Finally, I attached the light strips under the games. I didn’t want to make any permanent modifications to the games, of course, and want to be able to easily transfer the lights to a new game if I sell one and get another, so I used 3M damage-free hanging strips to attach these to the games, as well as wire hangers (not seen here) to run the wires to the back of the games.

The light bars are designed to have one strip of LEDs pointed straight down, and the other pointed down towards your feet at a 45 degree angle.

They work great and light up the carpet fabulously! So in the end, not only does the room look amazing, it’s quite a bit quieter too and the games sound better with less echoing!

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Funhouse Playfield Swapped!

Over the last few weekends, I’ve undertaken a new pinball project – swapping the playfield in my Funhouse, Pat Lawlor’s awesome game from 1990. My game was playing well, but definitely wasn’t the prettiest Funhouse out there. The clock inserts in the center of the playfield, in particular, were particularly worn:

I have a brand new reproduction playfield from Mirco to swap in, so away we go with the teardown! Here is a shot a bit closer in after removing the ramps and some plastics:

Notice how beat up the light inserts are. Also notice the ball lock mechanism – underneath the playfiled it’s actually a flipper mech! Very clever to re-use the mech and simply design a new top side part that can release one ball at a time by rotating (like a flipper rotates). Finally I was a bit surprised to see green tape under the ramp flaps. I’ve heard this came from the factory, but it’s not something I had ever seen before. Interesting!

Like I did with Space Shuttle, every single part I removed had its hardware individually bagged and cataloged. I filled about 60 ziplock sandwich bags of hardware on the top side alone. After the topside was mostly disassembled, I removed the playfield from the game and installed it on my rotisserie.

The playfield is now ready to get flipped over to the backside. At that point, my technique is to start on the new playfield and transfer parts as much as possible directly from the old to new playfield. The first thing to go in on the new playfield are the T-nuts and pop bumper bracket screws, because these parts are much more easily installed with an otherwise blank/empty playfield.

A luxury afforded to me this time was the use of a second playfield rotisserie! I borrowed my friend Marc’s who wasn’t using his at the time. It’s definitely not a must-have for a playfield swap, but I’d call it a very nice to have! Here is the new playfield installed on the second rotisserie. So shiny!

Then both playfields get rotated to the backside, and the transfer of parts continues. After the T-nuts and pop screws, I moved on to wiring harness hangers, other mech brackets, and the light boards. As I’m doing this, every switch and light is also being unscrewed from the old playfield.

At the end of the disassembly on the bottom side, the wiring harness is the only thing left and only gravity is keeping it on the playfield 🙂 I used the same technique as before of sliding in some cardboard pieces to pick up the wiring harness and move it over to the new playfield. Everything then gets screwed back in and mechs are rebuilt. I also took the opportunity to upgrade the flipper return springs to the newer WPC fliptronics style, but everything else about the flippers is stock.

Once everything is screwed back in on the new playfield bottom side, the rotisserie once again rotates back to the topside where re-assembly can start there!

Here is where all the time taken to meticulously catalogue hardware and take photos pays off. It’s pretty fast to take things apart, but going slow and taking a lot of notes makes it way easier at this phase.

The game got all new ramps and plastics, too, but this means some work re-riveting plastics attached to metal bits (which must be re-used). Of all the parts top-side, the step ramp took by far the longest to do – lots of stuff to transfer over! And although very little soldering was needed on this project, the step ramp switch wires are run through small holes and the only way to transfer them to the new ramp was to unsolder & re-solder.

Here’s the new playfield almost complete, just a few parts to go!

The playfield then went back into the cabinet and I went over all the solenoid lugs to make sure everything was clean and nothing was bent in a way that would create a short circuit. I plugged it in and powered the game on – no smoke, hooray! A few adjustments to switches were definitely needed, but fairly quickly the game was playable again, and plays better than ever.

This was my second playfield swap and it definitely went way faster than the first. It’s all known territory at this point, so way less time was spent thinking about how to do it and time spent doing it was very productive. The project took me about three weekends plus a few week nights here and there.

More photos of the completed game can be found here.

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Kraylix Complete…. for now

It’s been a while since I last posted about the Kraylix. I blame Street Fighter V! It’s just too fun! No sooner than I had the control panel, monitor and sound wired up to the Kraylix, I started playing both the old classics as well as SFV…. and well, time flies. SFV in particular is a really really fun game, and playing it on the Kraylix is great! I have many hours playing time on it now, but I thought I would go back and finally post a photo of the completed project.

As it stands now, here are some of the features of my Kraylix build:

  • Can run modern games (such as SFV) on the mini PC inside the cabinet.
  • Can run JAMMA & CPS2 games as well, with an XRGB Mini Framemeister upscaler
  • High quality built-in audio with a 2.1 channel amp, a pair of four-inch two-way speakers, and and 8 inch woofer for bass. I’m thrilled with how well this sounds!
  • Sanwa JLF sticks and Semitsu PS-14-KN buttons in a 6-up configuration. 8 buttons per player may be more modern, but I wanted the more old-school configuration. Who needs the extra two buttons anyway!
  • Built-in illumination including behind the marquee & move list, as well as ambiance lighting underneath the control panel and behind the cabinet.
  • Power controlled via a remote switch Tripp Lite power strip and arcade buttons hidden underneath the control panel to control the monitor and PC power.

Like I said in the title, I consider the cabinet complete, and although it’s totally playable, that doesn’t mean I don’t have some upgrades in mind for the future. Here’s a few projects I’d like to take on at an unspecified point in the future:

  • Arduino-controlled automatic power up of the monitor and PC. Right now, the power-on procedure is turning on main power followed by using the arcade buttons to turn the PC and monitor on. I plan to use an arduino to automatically power on the PC and monitor after main power turns on, which would enable a single-switch power solution (like a real arcade cabinet).
  • Re-print the marquee. I’m really happy with how my marquee turned out using a Duratrans print – the illumination looks just brilliant and the photo definitely doesn’t do it justice! That said, the mounting tabs in the cabinet obscure the backlight on the sides and top causing dark spots in the artwork. I think it would look better with a black border around the artwork. This would make the shadows at the mount points invisible for a much cleaner look. I did this for the move list and it turned out great, so I think the same effect on the marquee would be a big improvement.
  • JAMMA controls auto-switcher. As it is now, the procedure for switching between JAMMA games and the PC is a bit clunky. I have to go into the cabinet and unplug/re-plug the JAMMA connector. I’d like to build a JAMMA control switcher using diodes to allow the controls to be simultaneously wired to the PC and JAMMA games. The monitor already has two inputs, so doing this would allow for quick and easy switching between JAMMA and PC games.

I’ll post a photo of the current wiring/cabinet inside the next time I’m in there, but for now, see you in SFV online play 🙂


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Kraylix Back From Paint

Not too much to report tonight other than the Kraylix arcade cabinet is back from being painted! As described in previous posts, I had it painted with automotive paint – first a base layer of gloss black, then gloss clear.

Here’s a photo after having assembled the basic cabinet pieces together plus installing the marquee back panel that I painted white myself. Note the artwork on the control panel here is just office printer test prints to see what it will look like.Kraylix-painted 001

From what I heard the painter had to do a bit more sanding and filler (in addition to all the prep I did), but it was well worth it – I’m thrilled with how well it came out. The top arch in particular is totally seamless, as is the control panel. It doesn’t really even look like MDF or wood!

I’ll have to clean up some overspray on the control panel before mounting buttons and joysticks, but other than that it’s pretty much time for final assembly and wiring everything together. This has been a really fun project so far and it’s about to get even better!

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Added Remote Power Buttons to Kraylix PC and TV

With the gaming PC going inside the Kraylix cabinet and the Vizio TV behind a bezel, today I spent some time coming up with a solution to being able to power each on remotely as neither device’s power buttons will be accessible. There’s a couple approaches possible here, like trying to force each device to turn on automatically as soon as power is applied, but I decided against this and favored adding remote buttons instead for a few reasons:

  1. I won’t always be using the gaming PC. The arcade cabinet will sometimes be powered on and playing real arcade boards, not the PC. Therefore it shouldn’t simply turn on when power is applied.
  2. Forcing the TV power on doesn’t solve being able to choose the input (and I will be using multiple). That said, on my television the power button doubles as an input selector! It turns out on my model, a long press on the power button powers the set off, and a short press switches inputs. This means by wiring the button remotely I could control not just the power but also switch inputs. Perfect!

So I went ahead and cracked open the TV first. It took removing just a bunch of screws to remove on the back, and it popped right open. Super easy. Thankfully the power button was wired to the back of the TV with just two wires – it’s very likely a simple passive microswitch, which means I can splice in to that connection and run my own wires to my own button!Kraylix-powerbuttons 001

I went ahead and cut the power button wires, then soldered them back together with my two wires added:Kraylix-powerbuttons 002

I also drilled a small hole in the bottom of the plastic back panel of the TV to feed the wires through. A bit of wire routing and tape later, and the TV is ready to close back up.Kraylix-powerbuttons 003

Finally, the moment of truth – powering on the TV with my own button… It worked!Kraylix-powerbuttons 006

It’s an arcade button, of course, because that’s what will be used on the finished cabinet. I plan to make use of the hidden button slots on the bottom side of the Kraylix control panel for these power buttons.

Next up, my gaming PC. I could have quite easily spliced into the power button’s wiring harness the same way I did above, but I found it just as easy and a bit faster to simply solder my custom power button wires to the cases’s power button solder terminals, pictured below:Kraylix-powerbuttons 004

And bingo, this one worked too!Kraylix-powerbuttons 005

As you might be able to tell, I’m getting as many things done that I can while the Kraylix cabinet is still out to paint. I think when it’s back things should go together fairly quickly now!

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A Few Words on TPA3116D2 Audio Amplifiers

My plan for sound on the Kraylix arcade cabinet is to use two 4″ JL Audio speakers plus an 8″ woofer for bass. Of course part of having an integrated all-in-one solution for an arcade cabinet means some form of audio amplification is needed – I’m not about to cram a stereo receiver in the cabinet or something along those lines! Thankfully there are tons of decent and cheap audio amplifier boards available these days.

The TPA3116D2 is a popular chip by Texas Instruments used these days in audio amps. It’s very power efficient and hence doesn’t need a large heatsink. Small complete boards using these chips are extremely cheap and readily available on eBay for between 10$ and 20$ including shipping! I did a bit of reading on them online and it seems like results are mixed – but at those prices why not take a gamble and buy a few different ones to test them out? They seem like too good of an option to pass up, especially compared to other options for amps which can easily get in the 100$+ range. I bought three different ones in the “2.1” configuration (two main channels plus a subwoofer channel), each under 20$, hoping for at least one “good” one. I hooked them up to some small speakers plus an 8″ sub for testing. Here are my observations after listening to each for a few hours.

Heres’ the first board I tried:

Kraylix-audioamps 001

It didn’t have screw-down terminals for the speaker wires, so I had to solder the speaker wires in directly. Not a difficult task, but my speaker wire was fairly heavy gauge and the small holes on the board wouldn’t fit all the strands! I cut roughly half the strands away and soldered the speaker wires in. This board has a 1/8″ mini jack for line-in, and three dials – sub volume, main volume, and overall (sub+main) volume. So, how did it sound? Pretty decent, actually! I played a range of music and videos, including bass-heavy songs that would push its power consumption quite hard – no problems at all, and the board didn’t even get hot under prolonged testing. Then I paused the music and noticed a problem – an audible whining noise coming from the speakers. This board seems to have noise problems that are pretty obvious when audio isn’t playing back, no matter what the volume knobs are set to. Bummer. I even tried with two different power supplies (which are not included) but got the exact same results with both.

So, I moved on to board #2 to test, hoping for cleaner audio:Kraylix-audioamps 002

This board has the same volume control configuration, but came with nice knobs to install on the potentiometers. And notice how it also has screw-down terminals for not only the speaker wires, but also for the power supply in case you don’t have one with the right connector. Those are nice features over the first board. So how did it sound? Clean! Good sound at this one, and no audible whining noises! This one would work nicely in the arcade cabinet.

But I had yet another board to try out – here’s board #3:Kraylix-audioamps 003

The nice knobs came pre-installed, it has screw down speaker wire terminals, and it uses RCA jacks vs the 1/8″ mini-jacks on boards #1 and #2. I got nice clean sound out of this one, too! But the biggest difference between #3 and the other two were actually in the configuration of the dials – where as the first two had only volume controls, this board has two volume controls (sub, main) and the third knob is a low-pass filter frequency control for the sub channel. This is a very useful feature for tweaking the sound of the woofer, and for that reason I will most likely use this board in my Kraylix arcade cabinet.

Those were the main differences I found. There were some common points, too, though – they all produced very reasonable volume levels without any clipping, and none of the boards heated up much at all. The bass channel of all three sounded pretty similar, too, and although these boards are advertised as 2.1 channel (where the .1 is a subwoofer channel), I think it’s a bit of a stretch to call it a subwoofer channel. They all sound to me like the output drops off significantly below say 100hz or so. They’re more like a bass channel, which honestly will suit my arcade cabinet build just fine.

For what it’s worth, I have no idea how consistent the quality is on these boards, or why I got a whining sound from the first one but not the other two. It’s possible my board #1 was just a bad copy, but who knows. It’s hard to argue with the price – I think these boards are a tremendous value.

My plan is to install board #3 inside the Kraylix, right next to the coin door – this should allow for easy access to the volume controls while playing.

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