Best practive on power supply settings? Do vga encoder boards suck? (Need help before I fry something)

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    • Best practive on power supply settings? Do vga encoder boards suck? (Need help before I fry something)

      Hello all, I dove into this hobby about 2 months ago and all was going well. I built a basic jamma test rig to test boards out as I buy them. Its basically a control box with jamma harness and power supply built into it and one of these cheap CGA/EGA/YUV/RGB to VGA HD Video Converter Boards built into it to convert the display from the jamma harness to VGA (flatscreen monitor). I put 2 dedicated voltage meters on the power supply so I could see the levels of power coming from the 12v and 5v posts and found a bunch of youtube videos that said to set the dial so you are right at 12v/5v. So all was good I was having no issues playing with the little 60 in 1 boards and pandoras box fired up without issues, etc. Then I got a golden tee 98 board (huge board) and it absolutely would not turn on. after a lot of trial and error I found out that the board would not even boot until I turned up the dial on the power supply to 12.5v/5.23v and even then when it came on the test mode said "low voltage" so I kept slowly stepping it up slowly until it said voltage good. I was a little spooked, but went on with my day. Fast forward a week. Next I found 2 auctions for "Williams high impact football" I bid on them both hoping to win one, I actually won them both... and got 2 boards from 2 different sellers. This time neither of these boards would come up and display anything until I turned the power up too 13.0v/5.75v and when they finally did come on the picture drifts and flips really bad on both boards. And both sellers claimed they were just fine when they tested them. And when I asked what they tested them with I basically got an answer like "just a normal jamma setup"... uh really? thanks... So I suspected maybe the problem is with my test setup? I first suspected my power supply was bad. I have 2 other new power supply's of different brands, I tried them both with the same results. The odd part is I have a few other jamma boards besides the multicades, like tekken 2, dunkmania, etc. All display perfect. So I have a lot of questions that I have no idea who to ask. After going this alone I have come to the humble realization that I need some practical wisdom here. Hoping there is some jamma ninja out there that can give me some basic guidance.

      Question 1 - Power - All the service manuals for these games seem to just say the power requirements are 12v/+5v/-5v, yet it appears not all boards work with the same voltages even if their manual says they will. Is it safe to just turn the power supply all the way up just in case or will that damage the boards? How do ops deal with this issue, is every op out there screwing around with the power dial to see what works, or is there a best practice level to set your power supply too? Is there any recommendation for a power supply that works with most boards?

      Question 2 - display - Out of all the games I have at the moment I have become obsessed with trying to get High impact football working, mostly because I have 2 different boards that seems act exactly the same, which makes me suspect a problem with my test setup. Im starting to suspect the display drift, flipping, skipping and weird refresh problems to be an issue with the encoder board. I don't have an actual arcade CRT to try plugging in to see if that is better. Anyone out there know anything about this specific game? Power issues or display anomalies? Any recommendations for a display converter board that works good with old jamma boards besides these cheap $20 Jamma Game Monitor to LCD encoder boards? Should I say screw the encoder boards and go buy an arcade CRT? What typically gets the best results?

      Question 3 - what hardware should I be using? What do you use to test your boards? (display, power supply, harness brands?)
    • The 5V line is critical, too low a voltage and logic fails resulting in improper operation or no operation at all. Too high and bad things happen, like damage to the components on the board.

      You have much more tolerance within the 12V line. Most arcade boards use car audio amplifiers and will happily run between 9V and 21V.

      The 12V line in arcade power supplies is unregulated and is proportional to the 5V line. Turn up 5V and 12V goes up with it. The measured voltage will be dependent of the current draw of whatever is connected to that power rail, in the case of the 12V rail the draw is typically quite low, meaning the voltage will tend to run high.

      Measure from the arcade PCB and not directly from the power supply.

      Ensure you have adequate wiring, able to carry current of up to 15 Amps.

      In some cases certain boards will require more power, thus adjustment needs to be made. An example of this is dual or triple stacked boards that need to distribute power to more areas. Other things that can affect this is inadequate wiring, dirty connections, failing components etc. The idea of a multimeter reading exactly 5V and 12V in all cases is absurd and a huge misconception.
      Multi Boyz Club
    • Holy crap look at the replies! You guys rock! here are links to my gear ( this is NOT a commercial for amazon, its just to tell everyone what I'm using )
      cheap Chinese harness :
      amazon.com/gp/product/B01MT9MP…04__o00_s00?ie=UTF8&psc=1
      likely cheap Chinese Power supply:
      amazon.com/gp/product/B07F1D1Q…02__o00_s00?ie=UTF8&psc=1
      cheap Chinese Harness extension:

      amazon.com/gp/product/B01LXTYE…01__o00_s00?ie=UTF8&psc=1

      cheap Chinese encoder board for flat screen:

      amazon.com/gp/product/B01IBJCA…02__o00_s00?ie=UTF8&psc=1


      So I am adding some pictures (hope they work) Sorry if they look like they were taken with a toaster, the website said they were too large at first so I had to squash them down a bit.
      In this pic you see all of the above built into my ugly ass box (don't judge, just a test rig ) attached to the harness is one of my High Impact boards



      And this is the funk on the screen.

      In this pic the meter on the left is the +5v on the power supply, the meter on the right is the +5v on pin 1 of one of the IC's on the board. (I had no idea which one to test so I just picked one of the roms. )



      Then this picture of the encoder board with the messed up red circle that could barely draw with a mouse shows a specific button that I can hit on the vga encoder board after the board is powered on on and it seems to refresh the screen. But at this voltage it just updates to still images, in order to get it to move I have to move voltage up to the ones I described in my original post. The picture flips and is horrible but at least I can tell the game is in attract mode and moving. (but I am afraid to turn it up that high again because I don't want to fry these boards...




      Again keep in mind if I plug in say a pandoras box, a 60 in 1 or a namco board at this voltage, they start up fine...

      I actually got a Capcom bowling today and plugged it in and it runs like a champ. So again the reason I am obsessing over these Williams boards is they both seem to do the same thing which makes me think Its not the boards. The fact that it starts to move when I ramp up the voltage makes me think these boards don't like the power supply but also the weird thing with hitting the scan button on the encoder board, well... makes me think there is some kind of refresh problem on the encoder board. So this is why I am off on a crusade to see what kind of power supply's / displays other jamma guys are using, and if maybe anyone has run into any of the same types of problem. Different boards working at different voltages and some jamma boards having issues with these encoder boards. Legend has it there is a board called a supergun that might work better for display? Any info or suggestions greatly appreciated.
    • The jamma and extension harnesses are a problem. They use insufficient wiring on the power lines, the outer diameter looks fine but the inner conductor is too thin to handle large currents. Pandora's Box and 60-in-1s draw bugger all power so they will run fine, proper arcade boards draw more power and will struggle.

      If you can, remove the extension from the equation. Then replace the 4 x +5V and 8 x ground wires with good quality 18 gauge wiring.

      The video encoder has an auto button, usually pressing that will resolve most issues. There's also a menu button with various settings that may need adjusting. We'll get to that later though, let's sort out power first.
      Multi Boyz Club
    • Q1) All original boards should work @ 5.00V at the JAMMA edge, if not then a chip somewhere is faulty.
      Also as stated by @Frank_fjs the wires used in your setup for power lines are way too thin, a drop of 0.3V on such a short distance is huge.

      Q2) Those el cheapo encoders can cause all sort of issues. A couple of things to consider:
      - Have you adapted video signals and sync with resistors or are you using them coming straight from the game boards?
      - Try changing vertical position setting on the encoder to something >= 28.
      Looking for:
      - Sega Super Scaler hardware (Out Run, Model X, Model Y), not working (even with faulty PCM chip)



      "I'd 1cc games but I have a real life."
      01010011 01000101 01000011 01010010 01000101 01010100 00100000 01001101 01000101 01001110 01010101 00100000 01000111 01010101 01011001
    • I KNEW IT! I KNEW THERE WERE JAMMA NINJAS OUT THERE!!!!
      It is 5:37 on a Wednesday in Ohio and I just did the touchdown dance! which is really un-natural...
      I followed both your advice.
      -Ditched the jamma extender
      -set +5v to 5.31 (5.10 on the board)
      -Set the vertical position on the encoder to 28

      And I'll be dammed if one board popped up and played PERFECT! Its too early to find my phone and take a pic (I cant even remember my last name until I have coffee) I popped the other board on and it stops flipping as well. My 2nd board seems to have some other kind of graphics issue. Its in attract mode and the picture holds now but the graphics look kind of scrambled. But in a way that it makes me think there might be something wrong with ram/roms or something else besides the encoder... I will play with it more after work today and post a picture later.

      Ok before I ask more questions THANK YOU!!! Thanks PascalP, nem, and Frank_fjs for nailing the power problem and Apocalypse... dam, you truly are a master, your first suggestion nailed the display! Hats off to you my friends! I have been stuck on this for almost 2 weeks. These real deal arcade boards are obviously not happy with my cheesy equipment. So this raises a couple of questions and you guys are the right ones to ask.

      Q1 - Is there a better jamma harness you would recommend buying that has thicker wires? (18 gauge etc..) Or do I have to rewire it myself?

      Q2 - Why is vertical 28 value magic on the encoder board to keep the screen from flipping like it was? Is it like a standard arcade monitor resolution or is it specific to high impact or Williams games?

      The post was edited 3 times, last by deep6 ().

    • deep6 wrote:

      I KNEW IT! I KNEW THERE WERE JAMMA NINJAS OUT THERE!!!!
      It is 5:37 on a Wednesday in Ohio and I just did the touchdown dance! which is really un-natural...
      I followed both your advice.
      -Ditched the jamma extender
      -set +5v to 5.31 (5.10 on the board)
      -Set the vertical position on the encoder to 28

      And I'll be dammed if one board popped up and played PERFECT! Its too early to find my phone and take a pic (I cant even remember my last name until I have coffee) I popped the other board on and it stops flipping as well. My 2nd board seems to have some other kind of graphics issue. Its in attract mode and the picture holds now but the graphics look kind of scrambled. But in a way that it makes me think there might be something wrong with ram/roms or something else besides the encoder... I will play with it more after work today and post a picture later.

      Ok before I ask more questions THANK YOU!!! Thanks PascalP, nem, and Frank_fjs for nailing the power problem and Apocalypse... dam, you truly are a master, your first suggestion nailed the display! Hats off to you my friends! I have been stuck on this for almost 2 weeks. These real deal arcade boards are obviously not happy with my cheesy equipment. So this raises a couple of questions and you guys are the right ones to ask.

      Q1 - Is there a better jamma harness you would recommend buying that has thicker wires? (18 gauge etc..) Or do I have to rewire it myself?

      Q2 - Why is vertical 28 value magic on the encoder board to keep the screen from flipping like it was? Is it like a standard arcade monitor resolution or is it specific to high impact or Williams games?
      Hey.

      Many chinese jamma connectors do not have ground leads pin 28 and 27. Use paperclip to pull out unused pins and connect them to pin 28 and 27 and use them as ground lead. Should fix some issues.
    • Frank_fjs wrote:

      Do you have a CRT monitor at all, capable of accepting an RGB signal via scart?
      Unfortunately I don't. In fact seeing what people are charging for them, especially on ebay ($300-$500 some even $1000) I found the encoder boards for $20 as a cheap alternative. But I have been watching CL in my area to see if a good deal on one pops up. It would be nice to see the difference on a real crt.


      PekArcadeGamer wrote:

      deep6 wrote:

      I KNEW IT! I KNEW THERE WERE JAMMA NINJAS OUT THERE!!!!
      It is 5:37 on a Wednesday in Ohio and I just did the touchdown dance! which is really un-natural...
      I followed both your advice.
      -Ditched the jamma extender
      -set +5v to 5.31 (5.10 on the board)
      -Set the vertical position on the encoder to 28

      And I'll be dammed if one board popped up and played PERFECT! Its too early to find my phone and take a pic (I cant even remember my last name until I have coffee) I popped the other board on and it stops flipping as well. My 2nd board seems to have some other kind of graphics issue. Its in attract mode and the picture holds now but the graphics look kind of scrambled. But in a way that it makes me think there might be something wrong with ram/roms or something else besides the encoder... I will play with it more after work today and post a picture later.

      Ok before I ask more questions THANK YOU!!! Thanks PascalP, nem, and Frank_fjs for nailing the power problem and Apocalypse... dam, you truly are a master, your first suggestion nailed the display! Hats off to you my friends! I have been stuck on this for almost 2 weeks. These real deal arcade boards are obviously not happy with my cheesy equipment. So this raises a couple of questions and you guys are the right ones to ask.

      Q1 - Is there a better jamma harness you would recommend buying that has thicker wires? (18 gauge etc..) Or do I have to rewire it myself?

      Q2 - Why is vertical 28 value magic on the encoder board to keep the screen from flipping like it was? Is it like a standard arcade monitor resolution or is it specific to high impact or Williams games?
      Hey.
      Many chinese jamma connectors do not have ground leads pin 28 and 27. Use paperclip to pull out unused pins and connect them to pin 28 and 27 and use them as ground lead. Should fix some issues.
      I don't quite follow, run leads from 28 and 27 to one of the other ground wires?
    • deep6 wrote:

      Frank_fjs wrote:

      Do you have a CRT monitor at all, capable of accepting an RGB signal via scart?
      Unfortunately I don't. In fact seeing what people are charging for them, especially on ebay ($300-$500 some even $1000) I found the encoder boards for $20 as a cheap alternative. But I have been watching CL in my area to see if a good deal on one pops up. It would be nice to see the difference on a real crt.

      PekArcadeGamer wrote:

      deep6 wrote:

      I KNEW IT! I KNEW THERE WERE JAMMA NINJAS OUT THERE!!!!
      It is 5:37 on a Wednesday in Ohio and I just did the touchdown dance! which is really un-natural...
      I followed both your advice.
      -Ditched the jamma extender
      -set +5v to 5.31 (5.10 on the board)
      -Set the vertical position on the encoder to 28

      And I'll be dammed if one board popped up and played PERFECT! Its too early to find my phone and take a pic (I cant even remember my last name until I have coffee) I popped the other board on and it stops flipping as well. My 2nd board seems to have some other kind of graphics issue. Its in attract mode and the picture holds now but the graphics look kind of scrambled. But in a way that it makes me think there might be something wrong with ram/roms or something else besides the encoder... I will play with it more after work today and post a picture later.

      Ok before I ask more questions THANK YOU!!! Thanks PascalP, nem, and Frank_fjs for nailing the power problem and Apocalypse... dam, you truly are a master, your first suggestion nailed the display! Hats off to you my friends! I have been stuck on this for almost 2 weeks. These real deal arcade boards are obviously not happy with my cheesy equipment. So this raises a couple of questions and you guys are the right ones to ask.

      Q1 - Is there a better jamma harness you would recommend buying that has thicker wires? (18 gauge etc..) Or do I have to rewire it myself?

      Q2 - Why is vertical 28 value magic on the encoder board to keep the screen from flipping like it was? Is it like a standard arcade monitor resolution or is it specific to high impact or Williams games?
      Hey.Many chinese jamma connectors do not have ground leads pin 28 and 27. Use paperclip to pull out unused pins and connect them to pin 28 and 27 and use them as ground lead. Should fix some issues.
      I don't quite follow, run leads from 28 and 27 to one of the other ground wires?
      Pin E, F, 27 and 28 should all be ground. "run leads from 28 and 27 to one of the other ground wires?">>that is correct.