Monday, April 8, 2019

Captain America and the Avengers Repair Log #2

Next step was to remove all the chips for a deep cleaning.

It was even nastier underneath:

After using a nice paint brush to remove most of the dead insect parts and spider egg sacks, I prayed the entire board (both sides) abundantly with Simple Green.

Rinced it slowly in the sink after letting the Simple Green rest for a minute or two, then removed more stuck dead insect parts and did the same process once more for good measure.

I let it drain and dry a little bit, and then used my ESD protected Air Duster to push the excess water out of the sockets and help the drying process (now more than a minute or two at a time).

I let the board rest for a day and a night in the nice hot Californian weather, using the Air Duster a few more times once in a while.

Next step was to do a full visual inspection of the board.
  • Nothing major detected, no lifter legs on the legs of the chips, but a few scratches on the traces.
  • Used the multimeter to check continuity and all seemed fine.

Before doing more tests, I proceeded to cleaning the EPROMs and Pals.

  • One of the EPROMs had a bent leg that I managed to carefully salvage while cleaning it.
  • For the rest, I used a nail filer to carefully clean all the dirt off from the legs.
  • I then re-seated all of the chips in their sockets to do a quick test:

Color are back, screen is stable for the Attract mode!

I let it run for a while and all good!

Starting the game gives me still that debug code :/ 

But pressing start on player two made it disappear!!

Played the game for about 25 minutes with no issue!

  • Image good, controls good, sound perfect.

Success! It was an easy one!

Friday, April 5, 2019

Captain America and the Avengers Repair Log #1

I thought it was time for me to try repairing boards. I probably don’t have much of a knowledge about it outside of reading a bunch of logs, nor do I have half of the equipment, but we all have to start somewhere! The plan is to build both up as I go.

Writing this here will help me to stay accountable and hopefully receive some tips and advice :)

So got this Captain America and the Avengers from Data East for a low enough price, disclosed as booting but with issues, mostly sound.

It came in full of dust, and dead flies/cobwebs/egg sacks. Yikes. I brushed most of it off and will definitely Simple Green and wash it as soon as possible. This is after brushing it >_<

I noticed already some dirt and corrosion that I will have to look into once cleaned up

Booted it to do an initial check, and almost no image with a big loud buzz.
Pushing gently a bit on the EPROMs randomly managed to get me an image and eliminate the buzz! But the colors are wonky (missing).

Sometimes, the image gets garbled and pressing a bit on the board fixes it

Adding a credit to leave the attract mode, the sound plays good, music and SFX!

It seems like the debug is enabled though, and I will have to lookup the dip switch settings.

At least the game is alive and responsive. The fact that I can have sound, image and controls seems to be a good thing.

Next step will be to remove all the chips, give it a good cleaning overall, clean the sockets and legs and do a visual inspection to see all that can potentially be broken (traces, legs, etc).

To be continued!

Tuesday, March 26, 2019

K7400 Chassis repaired and cleaned up!

Fast forward from the last post, the chassis is finally ready!

All clean, all recaped, with a new flyback:

Neck board, with the 3 transistors changed and new capacitors:

Main Chassis, all capacitors changed and clean up:

New Flyback:

Cleaned up remote board:

And finally, installed in the Kyotaro:

For safety measure, I repeated the discharge steps with the monitor in case there was some electricity built up. Probably not needed, but you never know!

Unforuntaly, the cable for the Flyback is shorter than the original one. It does not seem to be a big deal as it's not touching anything, but having it so close to the Electron Gun and the Yoke makes me uneasy :P

I turned on the cab, and... Yes! No pop, no smoke, no smell of something burning, it works!

All the settings are out of wack though so I will need to have a tuning session as soon as I have enough time on my hand.

One of the thing that still bothers me is that my monitor seems to have either some purity issue or is hypersensitive to the magnetic fields around it (earth/house electric cabling/equipment) and suffers from discolorations in the corners, no matter where I put it. I'll need to work on that but that requires a lot more handling than I am currently comfortable doing, so it's time for more research. If I cannot fix this, then I will start looking for a new 27/29" tube compatible with the Wells Garder K7400 Chassis, and they don't come easy nowadays :/

Repairing the Wells Garder K7400 Chassis

One thing that everyone dreads with an Arcade Cabinet is a faulty monitor.
Mine started quite ok, after adjusting the colors and the geometry, but the more I played, the more I started to see signs of a tired Chassis:

  • The brightness was changing while playing, going darker then brighter out of nowhere.
  • Very rarely, it felt like it was losing a color for a short time
  • The screen started to have some hourglass shape after playing for a while or at start.

After consulting the super helpful people at Arcade Projects, there were definitely some faulty parts involved, and I would not cut it, it was time to replace all the capacitors of the chassis, and also while at it, the transistor of the neck board, attached to the tube.

I ordered a kit of Capacitor for my Wells Gardner K7400 from Arcade Parts and Repair, and the 27C3782 Capacitor from Mouser.

Next thing was doing the scariest part: discharging the monitor. For this, I used some high voltage protective rubber gloves, and the method that can be found everywhere on the internet: a cable with alligator clamps attached to a screwdriver.

 I added some electrical tape to the clamp around the screwdriver and attached the other side to the grounding harness that runs across the tube. A lot of websites recommend to attach it to the frame of the monitor, but the way mine was set up on the Kyotaro did not offer me that luxury. This is obviously the most important part, as you want the electric current to go to the ground so it can be correctly discharged and remove any risk of electric shock.

Then all was left to do is:

  • Remove any watch etc
  • Put the hand that does not hold the screwdriver behind the back, in the pocket or gripping a belt ring of my pants
  • Use the screwdriver to shot the connection where the anode plugs into the tube, repeat the process a few times to make sure and voila!

Wells, it took me a couple of weeks to find the courage to do it :P

Aided by a friend visiting me from France (emotional support and also here to call 911 in case I screwed up), and maybe a glass or two of wine, I finally decided to do it, expecting a big pop and/or an electric arc.

Well, nothing happened.

Turns out my monitor was resting for a while unplugged and recent enough to discharge automatically. Still better be safe!

Next thing was to start the work cleaning, changing all the pieces, and see.

Turns out that the Flyback on my chassis had a crack, and was probably why the brightness was changing like this.

Glad I also ordered a spare one ;)

Saturday, February 9, 2019

Some work on the Control Panel

Time for an update!

While working on doing a penal layout for both the panel itself and the panel bezel, based on the original Kyotaro artwork but change to accommodate the 6 buttons and the extra ones on the bezel added by the previous owner, I decided to upgrade the buttons and sticks.

Here how the original layout was, and while the NeoGeo colors was a nice touch, it just did not fit my tastes, making everything too busy and clashing with the purple theme of the Kyotaro 29. Also, I'm not super fond of HAP style buttons:

The current sticks were Sanwas, but the model is undefined. They are doing a good enough job, but I am more used to the Seimitsu LS-56.

So I made an order to Arcade Shock for the Following parts:

I then proceeded to remove the panel

I then realized that the Sanwa sticks on the panel are screwed on the center, and the new Seimitsu don't have a hole on the metal part.  I will need to drill some alter :( I just changed the balltops for now.

Then unscrew everything out and made a patter out the bare panel for future reference when working on the overlay later.

Snapped thenew buttons in, an voila!

Once I plugged everything back, there is the result. Pretty satisfied with it so far and looking gorward to change the sticks and work on the overlay!

Saturday, January 19, 2019

Kyotaro 29 - A little bit more about the monitor

After I set up the monitor properly, I decided to get more info on it.

Looking at the chassis, we can clearly see that it's a Wells Gardner (WG on the stickers). I did not want to take it out to know for sure what it was, so I took a few pictures and googled what I could see:


I used  mainly 2 resources for that:

The telltale was the "P numbers" on the chassis and the remote board. On the first picture, you can see P763, and the P790 (see previous posts) on the remote board confirmed it.

It's a 27" Wells Gardner 27K7401!

This will prove handy if I need to do anything on it later, but enough for today :)

Friday, January 18, 2019

Kyotaro, first power up

Plugged it, and it seems to work fine!

The image on the screen was completely off though:

- Super blurry
- Image all shrunk and misaligned
- Colors super off


After tinkering a little bit with the flyback, no more blurriness! The control board is located under the control panel, and turning a few dials took care of the image alignment and size. I also unplugged the P1 Start button doing so without realizing it, and that gave me a few seconds of frustration (looks like I will probably extend the cables for them as it's super tight at the moment).


Now the colors are not great, and I don't want to play them too much with today. I can also notice a clear sign of discoloration that probably would be solved by a degaussing.

I have the coil at hand...

Ok let's do it!

Following the advice gathered on forums and this very useful youtube video From Arcade Repair Tips, I use my Degauss Coil purchased at Fry's.

Slowly circling from 6 feet away towards the screen, then away from it for 1 min, the results are immediate!

Definitely look better, but the colors are still off. The white has a yellowish tint... Time to turn some RGB nods!

Locating them on the board of the screen was easy, and using a mirror I can finally see the colors come to light: not enough blue and too much red.

All done!

The image is now really good, which I was almost not expecting at this point. I still see some purple tint on the lower left corner but decide to stop there, taking in that the screen might be damaged.

After putting the cab next to my computer desk, I turned it on. And the image is really discolored on the left, side of my desk!

I then realize that the culrpit was my computer setup creating too much magnetic interference. Could be the speakers or everything else I have on there.

I decide then to put the cabinet in another corner of my office, and surprise! The picture is now perfect!

Sounds like a great way to end the day :)


(On this, still a small discoloration as I turned it close to the desk. Crazy how this setup is interfering with it!)