Testing a Taito Space Invaders Upright Power Supply

nerdygrrl

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Testing a Taito Space Invaders Upright Power Supply

I need to test the voltages on my Taito SI power supply model AA017741. Below is the best photo of the PS I could get. Has anyone ever worked on one of these before or could you recommend someone reliable that does SI work?

The issue seems to be coming from harness A and there looks to be some burn on the black pieces in front.

The monitor currently displays the mess on the end. Other fun fact, when I flip the switch to 120v the black lights kicks on. weeeee.

Thank you so much for your help
 

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All you should need to do is locate a ground point then probe into the molex connector where the schematic indicates the output voltages are. Measure and see if things read as they should and try using the adjustment pots to see if it needs adjusting.
 
I have had a lot of people contact me to tell me I have a Midway or that Taito didn't make SI uprights, or that they didn't make L boards.

Lol! :D

I still need to get the monitor in mine working.

C14 on the 14V line typically goes bad and will cause one of the fuses to blow.

The TAITO UPRIGHT manual at http://arcarc.xmission.com/PDF_Arca...Instructions_and_Parts_Catalog_(SV070019).pdf has the pinouts for the power supply towards the end and should help you figuring out which pin on the connector does what.

Homepin over on the Aussie Arcade forums drew up a great schematic for this PSU, available here: http://www.homepin.com/test/Taito_AA017741.pdf
 
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That80sGuy word thanks. This is the first voltage check I have done.

ataritoobin thanks for the pdf link and the heads up on the Aussie forum about the ps rebuild.

Good luck with your monitor. It is a beautiful and historic piece. I was so happy to find mine. It was my #1 must have as an SI fan.
 
From what I saw today, it seems someone as tried to use a Midway audio board with the Taito processor board. What you cannot see in the pictures is a bodge loom that has wires soldered onto the pins of the audio board and an edge connector card that plugs into the "proper" audio socket. Perhaps Melissa will insert a picture of said arrangement.
Also, all the ROM's are missing :-(
 
From what I saw today, it seems someone as tried to use a Midway audio board with the Taito processor board. What you cannot see in the pictures is a bodge loom that has wires soldered onto the pins of the audio board and an edge connector card that plugs into the "proper" audio socket. Perhaps Melissa will insert a picture of said arrangement.
Also, all the ROM's are missing :-(

I've heard of some instances where the Taito SI's used Midway PCBs (with Taito stickers) so it may be a stock job when they ran out of Taito-made PCBs? I can see if they used an adapter to the Taito harness but the soldered part sounds odd.
 
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I've heard of some instances where the Taito SI's used Midway PCBs (with Taito stickers) so it may be a stock job when they ran out of Taito-made PCBs? I can see if they used an adapter to the Taito harness but the soldered part sounds odd.

This is spot on. My boards have the Taito sticker with serial number, but are stamped midway made in the USA. I actually wrote to brentradio to see if he knew anything about this. I found it rather odd, but also knew there was a ton of demand for the game so I suspected some outsourcing.

I'll try and shoot some pics today.
 

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nerdy girl...

it was very common to have midway boards installed in japanese taito cabinets.

it was made like this from the factory.

taito allowed midway to act as a distributor for the usa markets and other countries around the world.
 
also can you do a photo of the bigger board that contains all the roms ?

your board is either faulty.. not connected to power on reset.. or has a ram issue.. hence why it looks messed up.
 
baz, thanks. I think quattrohead figured out the RAM issue. I am guessing since they are Midway factory boards I can just throw a set of Midway SI RAM in there.

Is the soldered rig pictured prior also factory issue? Have you seen that before?

If this is you collection http://img838.imageshack.us/img838/6041/55947337.jpg I am rather jealous. I am hoping to have an SI II upright shipped stateside within the year. I just love the Taito machines
 
Yep I'm working on a set for someone else that looks identical...Midway boards slightly modded for Taito cab (with the soldered loom for the daughterboard).
 
Yep I'm working on a set for someone else that looks identical...Midway boards slightly modded for Taito cab (with the soldered loom for the daughterboard).

Interesting, so it doesn't have the seven sound pots like on the Taito boards?

I'm sorry about all the questions information on this game is limited. You guys and the UK sites have been a god send.
 

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Thanks everyone, I think between here, the UK forums, and quattrohead's visit I have this all figured out.

The mish mash of Taito/Midway parts is now settled and I can move forward and hopefully get this beast up and running shortly.

The power supply is a Taito and I have tracked down a schematic for it thanks to ataritoobin. I will get around to testing it today or tomorrow.

The boards on this particular unit (lucky for me) were made by Midway so I just need to track down some eproms and get them programmed.

I am still interested in knowing more about the unit particularly how Midway compensated for the Taito sound card.

So far it's been a pretty interesting story.
 
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There isn't a big difference between the Midway audio circuit and the Taito audio circuit. Both designs have LM3900 pre-amp chips for each sound....invader hit sound, extra base award sound, missile shot sound, your man dying/explosion sound, etc. On the Taito boards....each sound has it's own volume pot. While Midway chose to output the pre-amp signals of all the sounds to one line and use one volume pot to control them simultaneously.

Edward
 
This is spot on. My boards have the Taito sticker with serial number, but are stamped midway made in the USA. I actually wrote to brentradio to see if he knew anything about this. I found it rather odd, but also knew there was a ton of demand for the game so I suspected some outsourcing.

I'll try and shoot some pics today.

"Real Taito" L-shaped boards have an edge connector on the sound board rather than the midway style .156" pins. On the bright side, since you've got a midway-style harness, it'll be a lot easier to find boards for it.

Tatio's L-set was based on Midway's redesign anyway. They were allowed to play with the hardware on the license, but not alter the software (beyond changing the default high score name).
 
The power supply is a Taito and I have tracked down a schematic for it thanks to ataritoobin. I will get around to testing it today or tomorrow.

Why do you need PS schematics to test it? Just measure the voltages at the edge connector. From the screen pics you posted, I'm guessing the voltages are fine. If you were missing -5 or +12 the video would be solid.
 
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